Monday, October 28, 2013

Marbled Chocolate & Pumpkin Cheese Tart



Earlier this month I shared a recipe for a very old favorite—Marbled Chocolate-Sweet Potato Cake.  Today I'm posting a new recipe—Marbled Chocolate & Pumpkin Cheese Tart.  I suppose I should apologize for posting two chocolate marbled squash/sweet potato recipes in such a short interval of time.   But since they're a bit different in style from one another...not to mention that they are both desserts and both delicious... it probably isn't necessary.    As I pointed out in my other post, even though the cake makes a pretty nice dessert,  it makes an even better breakfast (or snack).  The tart on the other hand is pure dessert.  And depending on the mode of your festivities, either one would make a fine treat to serve your adult friends for Halloween...which, as it happens, is right around the corner.

Most readers after taking a quick look through the tart recipe will think that the tart filling bears a striking resemblance to a cheesecake batter.  And they will of course be right.  It is cheesecake.  I have just chosen to bake it in a large tart pan.  I've done this for a couple of reasons.  First, it gives me a wider surface area on which to display the marbling...a striking and attractive contrast of orange and deep brown. 


Secondly, it allows me to cut wider slices (which will also show the marbling off to advantage in individual servings) that aren't so large as to founder my guests.  I like cheesecake...but it is almost always served in portions that are way too large.  Most of the time it is impossible to eat a full meal and then enjoy cheesecake for dessert.  When made in a thin layer...as with this cheesecake, or as in the key lime cheesecake I posted this summer...it is easy to serve small portions that don't look miniscule.


 
The flavors in this cheesecake are especially nice.  If you have never tried pumpkin with chocolate, I would encourage you to do so (this tart would be a great place to start).  I love this combination...it comes up a lot in my baking.  Besides the similar pairing of sweet potato and chocolate I posted a couple of weeks ago, I wrote about  a favorite pumpkin chocolate chip bar cookie a couple of years ago.  Although, when it comes down to it, I don't think I love this combination because pumpkin (or sweet potato) is particularly good with chocolate.  Rather, I think that chocolate is enhanced by the spices that are almost always found in pumpkin dessert preparations: ...ginger...clove...cinnamon...nutmeg...etc.  If you like, you can test my theory by sampling chocolate in combination with some of these spices—without any pumpkin—in a delicious Chocolate Gingerbread that I posted several years ago.

I mentioned at the first that both of these desserts would be nice as a Halloween treat.  But they would also be a great addition to your Thanksgiving celebration.  Besides being good for breakfast, the cake would be a great way to greet hungry travelers...along with a hot cup of coffee...or tea.  Whereas the tart would make an excellent stand-in on your Thanksgiving table for pumpkin pie.  This is a particularly good idea if you think pumpkin pie is just fine...and you'll make it and eat it because...well...it's traditional....   but in your heart of hearts, you would really rather be having something chocolate.


 
 
Marbled Chocolate & Pumpkin Cheese Tart

Chocolate Cookie Crust:
6 oz. chocolate wafer cookies, finely ground (2/3 of a 9 oz. package)
1 T. granulated sugar
2 oz. (4 T.) unsalted butter, melted

Butter a 10-inch removable bottom tart pan.  Combine the crust ingredients until homogenous and press onto the bottom and up the sides of the pan in a compact even layer. Place on a baking sheet and transfer to a pre-heated 350° oven.  Bake until set—10 minutes.  Cool.

Filling:
1 c. heavy cream, divided
3 oz. semi-sweet or bittersweet chocolate, finely chopped
3/4 c. pumpkin purée (180 grams)
1 t. vanilla extract
1 8-oz. package cream cheese, room temperature
3/4 c. sugar
1 1/2 T. all-purpose flour, sifted
1/4 t. salt
1/2 t. ground ginger
1/4 t. ground cloves
1/4 t. cinnamon
1/8 t. nutmeg
2 eggs, lightly beaten



Place a third cup of the heavy cream in a microwave safe bowl or a small saucepan.  Bring to a simmer.  Add the chocolate and set aside for a few minutes.  Whisk until smooth.  Set aside.

Combine the remaining 2/3 cup of cream with the pumpkin and vanilla; set aside.

 
Briefly beat cream cheese to break up.  Beat in the sugar until smooth; scrape the sides.  Combine the flour, salt & spices and beat in; scrape the sides.  Add the pumpkin mixture in three additions, beating until smooth and scraping well after each addition.  Beat in the eggs, just until smooth and fully incorporated.  Scrape down the sides.

Scoop out one cup of the batter (about 240 grams) and whisk into the melted chocolate mixture.  Scrape the remaining pumpkin batter into the cooled crust, spreading out to form an even layer.  Using a large spoon, dollop the chocolate batter evenly around the pan (eight dollops around the perimeter, plus one in the center works well).


Using the tip of a knife, swirl the batter attractively.  It works best to do this in large curves, sweeping across the entire pan and curving back the other way in a smooth repetitive motion.  It is always better to do less marbling than you think it needs...the contrast in the colors will be more striking this way.
 


Bake the tart in a pre-heated 325° oven until just set—about 30 to 35 minutes.  The filling will soufflé up a bit around the edges but will still be a bit jiggly in the center. 



Cool to room temperature (about 2 hours).  Chill, uncovered, until cold (at least 2 hours, but cheesecake may be baked a day ahead). 

To portion, remove the sides of the pan and cut using a sharp, thin knife dipped in hot water (and wiped dry) in between cuts.  Serves 10 to 12.
 

Wednesday, October 23, 2013

Winter Squash & Rice Gratin



I mentioned a few posts back that I enjoy teaching cooking classes that are organized around one ingredient or a seasonal group of ingredients.  "Single-ingredient" classes are interesting for a lot of reasons, but there are two particular things I always focus on when I'm preparing for this kind of class.  The first is technique.  A class where one ingredient shows up in four or five recipes is a perfect opportunity to talk about how that ingredient responds to a wide variety of techniques...blanching, roasting, sautéing, braising, etc.  Since it's easy to get in a "food rut"—always blanching green beans...or roasting corn...etc.—I hope that by covering a variety of techniques people will be inspired to try something new.  The second thing I like to highlight in a single ingredient class is flavor combinations.  There is of course no way I could possibly demonstrate all of the possible natural flavor partners a single vegetable or fruit might have...but just showing a few—and discussing a few more—is enough to get people's creative juices flowing.  And when I think about it, a foundation of good technique along with an understanding of the interplay of flavors is pretty much what good cooking is all about. 

Recently I have been working on recipes for a new single-ingredient class featuring winter squash and sweet potatoes.  Two of the recipes have already appeared here on my blog (Sweet Potato Pancakes with a Medley of Corn, Sweet Potatoes & Black Beans and a Kale, Sweet Potato & Chorizo Soup).  Between these two recipes I will get to demonstrate three techniques (roasting for a purée, sautéing and poaching) as well as a variety of interesting flavor partners for these two vegetables (sweet corn, bitter kale, spicy-salty cured sausage).  I included the recipe that I am posting today in the class because it illustrates a simple technique for braising squash (borrowed from a pasta recipe I posted a couple of years ago) that produces nice, tender, intact chunks of squash.  For a detailed explanation of the technique, you should check out that post.   In the area of flavor combinations, this gratin features one of my favorites—squash (or sweet potatoes) with mushrooms.  I love the contrast of the earthy mushrooms with the sweet squash.  On my blog this pairing has shown up in a pizza, a pasta and a simple vegetable gratin.  I guess you could say this is one of my own personal food ruts.  But not everyone has tried this combination...the beauty of cooking is that one person's rut is another person's uncharted territory.  As a bonus, the recipe includes three other natural partners for squash: salty bacon, salty-nutty Gruyère and sweet, rich leeks.


The inspiration for this recipe is mostly from a summer squash, rice and leek gratin featured in Vegetarian Suppers from Deborah Madison's Kitchen.  But as Madison says, her recipe is simply a specific example of a homey kind of Provençal rice gratin.  While I was staying in Provence I sampled a winter squash version that included Ham and onions as well as a bit of cream.  And while working on this recipe, I ran across one on line that included winter squash, bacon, leeks and a bit of Greek yogurt.  My final recipe is a blending of these three (with the addition of mushrooms).

The basic idea for this style of gratin is to combine cooked rice with roughly an equal quantity of cooked vegetables (I like a bit more vegetables than rice...but it's up to you), spread the mixture in a shallow baking dish,  top it with breadcrumbs and bake until hot and golden.  The vegetables you use shouldn't be too dry... and similarly it isn't a problem if the rice is a bit wet.  The gratin may be enhanced with cheeses, cooked meats, olive oil or the aforementioned cream. 

I have written the recipe assuming that you will make all of the components, combine them and bake them right away, but you could always assemble the gratin ahead and refrigerate it until you are ready to bake it.  You should bring it to room temperature before baking.  Even so, you will have to increase the baking time just a bit to account for the fact that all of the individual ingredients aren't already hot.

I suspect that in its original incarnation this kind of gratin was a way of using up leftovers.  So if you happen to have some leftover cooked rice on hand...and you have a pile of the current season's squash on your kitchen counter, this would be the perfect thing to make for dinner.  If by chance there is anything left over...it will make a terrific lunch.

Leftover lunch...with a salad and an apple
 

Winter Squash & Rice Gratin
with Mushrooms & Leeks

2 slices bacon (2 oz.), cut cross-wise in 1/2-inch pieces
2 c. diced (scant 1/2-inch) winter squash (10 oz.)—butternut, red kuri, etc.
2 1/2 to 3 T. olive oil, divided
4 oz. Crimini or white button mushrooms, sliced 1/4-inch thick
1 medium leek, white and pale green part only, halved, sliced cross-wise into 1/2-inch pieces and rinsed in several changes of water
1/2 to 1 t. each minced fresh thyme and sage
1/2 c. chicken stock
1/2 c. Basmati rice
1/2 c. coarse, fresh breadcrumbs (from day-old bread is perfect)
2 oz. coarsely grated Gruyère
Salt & Pepper

In a medium-sized sauté pan (something wide enough to hold the squash in a snug single layer...a 9- or 10-inch cooking surface is about right), render the bacon over medium-low heat until crisp.  Remove the bacon to a plate and increase the heat to medium-high.  (Pour off some of the fat if the bacon was very fatty...there should be about a tablespoon of fat in the pan.)  Add the squash and toss to coat in the fat. Sauté (tossing occasionally) until the squash begins to caramelize in spots—about 5 minutes. Reduce the heat to medium if the squash threatens to burn. 



Remove the squash to a plate and return the pan to the heat.  Add a tablespoon or so of olive oil to the pan and toss in the mushrooms.  Sauté until softened and beginning to brown—about 3 minutes.  Reduce the heat to low and season with salt.  If the pan seems dry, add a bit more olive oil.  Add the leeks to the pan, along with a pinch of salt and cook until wilted, stirring frequently.  Don't let the leeks brown—if necessary reduce the heat even further and cover the pan to encourage the leeks to wilt.  


When the leeks have softened a bit (after about 5 minutes), return the squash to the pan along with half of the herbs.  Season lightly with salt (be careful with the salt—bacon and Gruyère are salty and too much salt will mask the sweetness of the squash).  


Add the stock to the pan and bring to a simmer. The stock should come about 3/4 of the way up the sides of the vegetables—add water if necessary. 


Gently simmer (uncovered and stirring every now and then) until the squash is just tender—about 25 minutes. As the liquid reduces, add water occasionally to maintain a level of liquid that is about 1/4 to 1/3 up the sides of the squash.  When done there should only be a small amount of liquid remaining in the pan. 

While the vegetables simmer, cook the rice using whatever method you prefer (boil, steam, etc.).  For plain rice, I prefer to use a method similar to something Alice Waters calls "the absorption method" in her book The Art of Simple Food:  Place the rice in a heavy bottomed sauce pan (for 1/2 cup a 2-quart size is fine).  Add a cup of water along with a pinch of salt and a drizzle of olive oil or butter (about 1/2 T.).  Place the pan over high heat and bring to a boil.  Allow the rice to boil (undisturbed) rapidly until most of the water has evaporated (if you tilt the pan, you shouldn't see any water) and the surface of the rice is covered with steam holes.  Cover the pan.  If you have an electric stove, transfer the pan to a burner set at the lowest setting.  If you have a gas stove, simply reduce the heat to the lowest setting.  Allow the rice to steam for 12 minutes.  Turn off the heat and let sit (covered) for another 5 minutes.  Uncover and fluff. 

Toss the breadcrumbs with the remaining herbs and a half tablespoon of olive oil.  Set aside.

To build the gratin, combine the rice, vegetables (along with any liquid in the pan) and bacon in a large bowl.  Add the cheese and fold in just to distribute evenly.  Turn the contents of the bowl into an oiled 1 1/4- to 1 1/2-quart gratin or shallow baking dish.  


Spread the prepared breadcrumbs over the top.  If you like, drizzle with more olive oil.  


Bake in a preheated 375° oven until sizzling around the edges and hot through—about 20 to 25 minutes.  If the surface is not golden brown, simply run under the broiler for a few moments.


Serves 4 as a side, 2 as an entrée.

Note: To cut down on prep time, you can sauté the mushrooms and squash in a second pan.  Simply cook the bacon, remove it and then wilt the leeks in the bacon fat.  While the leeks and bacon cook, sauté the squash and then the mushrooms in a bit of olive oil in a separate pan  (preferably non-stick—if you don't have a non-stick pan, deglaze the pan with a bit of water and add this to the braise).  Add the mushrooms & squash to the leeks and proceed with the recipe.



As a side with pork and salad greens
 

Tuesday, October 15, 2013

Marbled Chocolate Sweet Potato Cake


Last month I shared a recipe for one of my favorite autumn cakes.  Since I have posted many other favorite season-specific cakes in the past (rhubarb cakes in the spring...stone fruit in the summer...dried fruit and nuts in the winter...) it should come as no surprise that I would have more than one or two cakes on my list of fall favorites.  I have been making the cake I am sharing today for many years...so long in fact that the cookbook from which it comes (The Victory Garden Cookbook) is out of print.  It is made with sweet potatoes (which are coming into season right now), chocolate and spices....and it is simple and delicious. 


In character this cake is like a loaf cake or a tea bread.  It is moist with a fine, even crumb.  It slices beautifully into thin slices...or fat wedges.  I serve it as a dessert...but it is such a large cake there are always leftovers and it makes a pretty fine breakfast.  The slices freeze well too...making it appropriate for keeping on hand for a sweet something with afternoon coffee or tea.  The recipe directs you to bake it in a large tube pan (the type of pan used for Angel Food Cake)...but it can be made in two 8-cup loaf pans instead.  When I teach this recipe in my Winter Squash & Sweet Potatoes class, I always make the tasting cake in loaf pans.  It is easy to get a lot of  even, thin, tasting-sized portions in this form.  For this reason, the loaf style would also be perfect for a pot luck or a church coffee hour.

You might think that this cake could just as easily be baked in a Bundt pan, but I would not recommend this.  Even large Bundt pans will only have a 12-cup capacity.  This cake requires a 16-cup pan.  It may look like it will fit in your Bundt pan, but it will tend to want to overflow while it bakes.  Even if I happened to have a large enough Bundt pan, I would still choose to make this cake in a single tube pan or two loaf pans.  The exposed surface of the finished cake is an attractive, rustic coil of dark orange and deep chocolate brown.  Because a Bundt cake is always inverted for serving this marbled surface would be hidden from view.  Both the tube and the loaves are presented "right-side" up, so the pretty top of the cake remains on display. 


In all likelihood this cake will remind you of pumpkin bread.  But you shouldn't be fooled into thinking that it can be made with pumpkin.  It cannot.  If you have ever tasted plain roasted sweet potatoes and thought to mentally compare it with the flavor of plain pumpkin purée, you will know that sweet potatoes are naturally much sweeter than pumpkin.  The recipe takes this into account; there is not enough sugar in the cake to support pumpkin.  Since it is much more convenient to open a can of pumpkin than it is to go to the trouble of roasting and puréeing a few sweet potatoes, the temptation to do so is great.  But I know from experience that you will be disappointed.  Even with this extra step of preparing the sweet potatoes, this is still a very easy cake to make...and definitely worth that little extra effort.  

As with most cakes of this style, it really needs no special adornment....a sprinkling of powdered sugar is sufficient.  That said, there are many things that would compliment this cake nicely. A glaze of some kind would be good...either a simple powdered sugar-based glaze or a chocolate glaze.  A crème anglaise or a chocolate sauce would be delicious, too.  To be honest, I like it best served with a small scoop of ice cream.  I have served it with vanilla...and several years ago I discovered I like it with Ben & Jerry's Heath Bar Crunch.  This last time however, I made my own ice cream to go with it...a delicious espresso bean ice cream.  And I have to say I think this was probably the best combination yet.


  
Marbled Chocolate-Sweet Potato Cake

3 c. all-purpose flour
2 t. baking powder
2 t. baking soda
2 t. cinnamon
1/2 t. ginger
1/4 t. ground cloves
1/4 t. nutmeg
1 t. salt
1 c. walnuts or pecans—lightly toasted and coarsely chopped
2 c. mashed cooked sweet potatoes—about 18 oz. of purée (see note)
1 1/2 c. vegetable oil
1 1/2 c. sugar
1 t. vanilla
4 large eggs, at room temperature
4 oz. semi-sweet chocolate, melted and cooled


Butter and flour a 10-inch tube pan or 2 8-cup loaf pans.  Set aside.  Whisk the dry ingredients together.  Stir in the nuts and set aside.

In a stand mixer, using the whisk attachment, beat the sweet potatoes, sugar, oil and vanilla at medium speed until very smooth and glossy.  (Or, whisk by hand in a large bowl).  


Whisk in the eggs one at a time, making sure each egg is fully incorporated before adding the next.  By hand, fold in the dry ingredients and the nuts.  Scoop one third of the batter (about 21 oz.) into a separate bowl and quickly stir in the chocolate. 

Place the batters in the pan(s), alternating as for a marble cake.  


Then, with the end of a wooden spoon or the blade of a table knife, gently draw swirls through the batter to marbleize it.  Don't over mix or you won't have a marble affect—two, zig-zag passes through the pan should be sufficient. 


Bake in a 350° oven until the cake springs back and a toothpick inserted in the center comes out clean—about an hour for the loaves and an hour and 10 minutes for the tube cake.  Cool in the pan for 10 minutes before transferring to a wire rack to cool completely. 


Note:  You will need about 2 lbs. of sweet potatoes to produce 2 cups of purée.  Roast the sweet potatoes in a 400° oven.  Prick the sweet potatoes in several spots with a fork or paring knife and transfer to a baking sheet.  Bake until easily pierced with the tip of a knife, about 40 to 60 minutes—the potatoes will have begun to ooze a bit of sugary syrup when they are fully cooked.  When cool enough to handle, cut open the sweet potatoes and scoop out the flesh.  Purée in the food processor, or press the flesh through a sieve or mesh strainer.  A sweet, orange fleshed variety of sweet potato (like Garnet, Jewel or Beauregard) will give the best result for this cake.

 (Recipe adapted from The Victory Garden Cookbook, by Marian Morash)



Espresso Bean Ice Cream

2 c. milk
1 c. coffee beans
2 c. cold heavy cream
8 egg yolks
1 c. sugar
pinch of salt
1/2 T. pure vanilla extract
4 t. very finely ground coffee beans (espresso grind)

Place the milk in a small saucepan.  Add the coffee beans to the pan.  Bring to a simmer.  Remove from the heat, cover and let steep for 1 hour.  While the milk is infusing, pour the heavy cream into a large bowl and refrigerate.

Strain the milk into a clean saucepan (discard the coffee beans), add half of the sugar and return the pan to high heat.  Place the egg yolks in a large bowl with the remaining sugar and salt and whisk until thick and pale yellow.  Take the bowl of chilled cream out of the refrigerator and place a strainer over the bowl; set aside near the stove. 

When the milk boils, temper the egg yolks by gradually whisking in about a cup of the hot milk.  Stir the tempered egg mixture back into the saucepan and place the pan over medium heat.  Cook, stirring constantly with a heat-proof spatula, until the custard is thickened.  (If you dip a spoon in the custard and draw your finger across the back of the spoon, a path will remain.  Also, an instant read thermometer will read about 170°.  The custard must be cooked beyond 160°, but must not go over 180°.)  Immediately strain the custard into the bowl of cold cream.  Stir in the vanilla.  Place the bowl of custard in a larger bowl of ice water and let cool, stirring occasionally.  Cover and refrigerate until deeply  chilled.

When ready to freeze the ice cream, whisk in the espresso.  Freeze the ice cream in an ice cream machine according to the manufacturer’s instructions.  Transfer to a freezer container and freeze for an hour or two—or preferably overnight—before serving.  Makes about 1 quart ice cream.

(Recipe inspired from The Perfect Scoop by David Lebovitz)



Thursday, October 10, 2013

Potato Gratin with Fennel & Tomatoes


I love that brief moment every fall when the days are warm and sunny...the nights are downright chilly...and the farmers' market is filled with not only the abundance of the new season (winter squash, sweet potatoes and other root vegetables, apples & pears, greens...) but also the final odds and ends of the summer crop (tomatoes, peppers, eggplant, green beans...).  Some of my favorite foods fit neatly into this moment—foods that utilize the remains of the summer produce in ways that satisfy my natural craving for the warmer, heartier foods of Autumn:  corn chowder made with chunks of sweet potatoes, Moussaka, rich warming stews of eggplant, tomatoes and summer squash or polenta with the last of the sweet corn folded in.  For dinner a few nights ago we had a potato gratin that fits perfectly into this short in-between season. 


I don't remember the original inspiration for this particular gratin.  I made it for the first time over ten years ago.  I suspect that it is a dish that came about as a way to use up the remainder of a large head of fennel (my original notes call for half of a head of fennel).  Since I would have recently returned from Provence around that time, a French-style gratin filled with the very Provençal flavor combination of fennel, tomatoes, garlic and thyme would have been an obvious direction to go.   

This is not a gratin that I think to make every year.  The inclusion of vine-ripened tomatoes makes it a bit unusual.  Often the tomato crop is over by the time I'm in the mood for a potato gratin.  But as I have mentioned in previous posts, this has been an amazing year for tomatoes.  And now, even as the waning of the light has signaled to the tomato plants that it's time to slow down production, the tomatoes are comparatively abundant and I have continued to bring home as many as I think we can manage to consume in a week.  I am still enjoying them sliced and simply dressed with salt, pepper, vinegar and olive oil, but a large portion of them are now making their way into the aforementioned stews and casseroles.  A couple of Jet Stars were just right for this gratin. 


Up until a year or two ago I had always made this particular gratin with all broth.  Then, I ran across a similar recipe that included a bit of cream. This small amount of cream is inspired—adding much more in the way of warmth and richness than one would anticipate from its volume.  You can of course make the gratin with just broth (see the notes at the bottom of the recipe)...and doing so will make a lighter gratin (fitting even for the still hot temperatures of late summer)...but I really prefer it with the cream.

I love everything about this gratin.  It is rich without being heavy, in sync with the season, and filled with flavors reminiscent of one of my favorite places in the world....satisfying in every way.  So, if you happen to have some late season tomatoes sitting on your counter....looking for  a home...you should give this a try.  Or, if you get up this Saturday morning...and it is chilly and dark...and the thought of your bed is more appealing than a cold trip to the farmers' market...  Think of those last tomatoes....and the possibility of this gratin for dinner...and then get up and go.



Potato Gratin with Fennel & Tomatoes

1 T. olive oil, more as needed
1 small (or half of a large) bulb of fennel (weight when trimmed of stalks should be about 6 oz.), halved, cored and sliced very thinly (use a mandolin) crosswise—you should have about 1 cup of sliced fennel
1 small (or half of a medium) onion (4 oz.), thinly sliced
2 cloves garlic, thinly sliced cross-wise
Salt & pepper to taste
2 small or 1 large tomato (1/2 lb.)
1 1/2 lb. russet or Yukon gold potatoes
2 to 3 t. picked thyme, coarsely chopped
1/2 c. Heavy cream
1/2 to 3/4 c. chicken (or vegetable) stock
1/3 c. grated Parmesan (1 oz.)

Warm the olive oil in a medium sauté pan set over medium heat.  Add the fennel, onion and garlic along with a pinch of salt and toss to coat in the oil.  When the vegetables begin to sizzle, reduce the heat to low, cover and cook until just tender—about 15 to 20 minutes.  Set aside.



While the onion and fennel cooks, peel the tomatoes (by blanching and shocking or using the method outlined in this post).  Place a sieve over a bowl, halve the tomatoes crosswise and remove the seeds while holding the tomato halves over the bowl.  Thinly slice the tomatoes halves and reserve separately with their juices. 

To build the gratin, lightly oil a shallow 1 1/2 quart baking dish.  Peel the potatoes and using a mandolin, slice the potatoes crosswise very thinly (1/16-inch).  Shingle half of the potatoes into the gratin in overlapping rows.  Season with salt, pepper and a third of the thyme.  


Spread the fennel-onion mixture over the potatoes in an even layer and season in a similar manner. 


Next, layer in the tomatoes, spreading evenly.  Pour the reserved tomato juices over the tomatoes.  Season with salt, pepper and the remaining thyme.  


Layer in the remaining potatoes and season with salt and pepper.  


Pour the cream over all, jiggling the dish slightly to make sure the cream penetrates all of the layers of vegetables.  Pour in enough chicken stock so that the vegetables in the middle are just barely covered with liquid when pressed with a spatula or your hands. 


Cover the gratin tightly with foil and place on a baking sheet.  Place in the center of a preheated 375° oven and bake until the cream and stock are bubbling around the edges—about 30 to 40 minutes.  Remove the foil, scatter the Parmesan evenly over the gratin and continue to bake until the cream is reduced and bubbling thickly, the top is a beautiful golden brown and the potatoes are tender to the tip of a knife—another 30 to 40 minutes.  Cool briefly before serving.  Serves 4 to 6.


Notes:  To make the gratin without heavy cream simply omit it and add stock to the appropriate level in the dish—you will need 1 to 1 1/4 cups of stock.  Drizzle the gratin liberally with olive oil before covering with foil.  I have never tried it, but I think this all-stock version would be delicious with saffron.  To make, steep a pinch of saffron 3/4 cup of the hot stock before pouring it over the gratin.  Again, add as much more plain stock as is necessary to properly moisten the gratin.