Creamy Asparagus Soup

In my last post I mentioned that I included a recipe for Asparagus Soup in my all-asparagus class. Since we are in the height of asparagus season—and the weather has turned cold (again)—it seemed like a timely topic for a post. Although it doesn't have to be cold out to enjoy this soup. More than one person who tasted the soup commented that it would make a fine cool or chilled soup for the hottest days of spring. I happen to prefer the soup hot...but no matter what the weather is like...and no matter what temperature you choose to serve the soup...it is a perfect recipe for the peak of the asparagus season.

More than anything else I taught in my class, this soup is a pure celebration of asparagus.  There really isn't much in it besides asparagus. A quick scan of recipes on the web, or in your cookbook collection, will show that this tends to be the norm for cream of asparagus soups. Recipes usually include some kind of onion, stock or water, asparagus and a little cream. Occasionally you will find a recipe that uses some flour or adds a potato for thickener. But in my opinion, these things function more as extenders than thickeners. Your soup will have a perfect thickness without them if you use a sufficient quantity of asparagus.

I can't take credit for the recipe that I'm sharing today—and I'm not quite sure of its origin. I learned to make it when I was a line cook at The American Restaurant. At The American, the soup functioned as a way to use up all of the "unusable" tough ends of the asparagus. There was always an asparagus side dish on the menu. No matter how it was presented, it seemed to fly out the door. People love asparagus. So even if there seemed to be nothing in the house to make soup with, there was always an abundant supply of the tough ends of the asparagus that could be turned into this soup.

I have altered the idea of the original recipe only slightly in that I use the tender portion of the asparagus too. Most home cooks won't use enough asparagus to be able to make soup with just the discarded ends. A recipe that uses the entire stalk of asparagus is more practical while still being economical. I mentioned in my last post that the tough ends make up nearly fifty percent of the pre-trim weight of the asparagus. Since a small batch of soup requires two pounds of asparagus, if you were not using the ends, you would need to purchase four pounds of asparagus to make the soup. This would be an expensive soup—and is no doubt the reason that some recipes resort to using flour or potatoes to make the asparagus go further.

When you make a soup that uses the tough ends, you must strain the soup through a fine-meshed sieve before serving it. A simple bowl shaped, fine-meshed sieve will do, but a conical fine-meshed sieve (called a Chinois) is even better. When straining a liquid with lots of little fibrous bits, you must press firmly on the solids (with a ladle, or other suitable implement) in order to extract the maximum amount of liquid. A conical strainer consolidates all of these solids into the tip of the cone, making the pressure you apply more effective. If you do not own a fine-meshed sieve of any kind, or you don't wish to strain the soup, then when you purchase the asparagus for the soup, purchase twice as much as the recipe calls for and discard the tough ends instead of adding them to the soup.

Fibrous solids that remain after passing the soup through a sieve

The other thing that makes the recipe that I use different from other recipes that I have seen is the final color. By the time asparagus is cooked to the point that it is soft enough to purée, it has become a very drab army green. I suppose there is nothing wrong with this...it is after all a natural color...but your soup doesn't have to be such an unattractive color. To produce a beautiful, spring green soup, just add some fresh spinach to the blender as you are puréeing the hot soup. The spinach will purée smoothly in, turning the soup a brighter green in the process.

 Many recipes instruct you to reserve a few of the asparagus tips for garnish. They are blanched separately and then scattered over the surface of the finished soup where they are supposed to float. But they will only float if your soup is pretty thick—too thick, in my opinion. A better way to use the tips is to prepare some little goat cheese crostini—which will float nicely on the surface of the soup—and place an asparagus tip or two on top of the crostini. There they will be visible. The crunchy crostini will soften quickly in the soup and the goat cheese will provide a nice bit of tangy flavor to two or three spoonfuls of each serving.

Goat cheese crostini—with or without the addition of the asparagus tips—are just one idea for garnishing this simple soup. There are many other possibilities. A particularly elegant and seasonal garnish would be a few halved or sliced morels. Simply poach them in a little bit of butter and stock (or water) and add them to each serving. Other simple garnishes include a pat of a favorite compound butter (floated on the hot soup where it will melt and leave a flavorful puddle that each diner can then stir into their soup), a drizzle of extra virgin olive oil, or a dollop of crème fraiche. I typically think of this as an elegant, first course type of soup, but it would make a nice lunch soup too...accompanied by a grilled cheese sandwich...or maybe a prosciutto and cheese panini....

In the end, it doesn't really matter how you serve it, as long as you take the time to make it before asparagus season draws to a close. Asparagus may be available year round, but it is at its best and its most abundant right now. In just a few short weeks its season...and the moment for this soup...will have passed.

Cream of Asparagus Soup

2 lbs. asparagus, well-rinsed to remove grit from tips
4 T. unsalted butter
8 oz. shallots (about 4 medium), peeled and thinly sliced
5 c. water (or use half water and half chicken stock)
4 to 5 oz. spinach (several handfuls)
3/4 c. heavy cream
Salt & Pepper, to taste
baguette, sliced 1/4-inch thick
olive oil
1 clove garlic, peeled and halved
4 oz. soft goat cheese, crumbled
2 T. minced chives

Prepare the asparagus: Snap off the tough ends. Split lengthwise and then cut roughly crosswise 1/2- to 1-inch thick. Set aside. Slice the tender stalks and tips crosswise 1/2- to 1-inch thick and reserve.

Melt the butter over medium heat. Add the chopped tough ends of the asparagus and the shallots, along with a pinch of salt. Cover the pan and gently sweat until the shallots are beginning to soften—about 5 minutes.

Add half of the liquid to the pan and bring to a simmer. Cover and reduce the heat. Simmer gently until the tough ends are tender—20 to 30 minutes. Add the remaining asparagus along with enough of the remaining liquid to just cover the solids. (You can always add more liquid when you are puréeing the soup, but if you add too much now, the soup will be too thin.)  Salt to taste. Gently simmer until all of the asparagus is quite soft—about 15 to 20 minutes.

While the soup cooks, make the crostini garnish: Distribute the sliced baguette on a baking sheet in a single layer and brush liberally with olive oil. Place under the broiler and broil until the toasts are golden; turn the slices over and broil the second side until golden. Scrub the warm crostini lightly with the cut surface of the garlic. When the crostini are cool, top each with goat cheese crumbles.

Purée the finished soup in batches, adding a handful of spinach to the blender with each batch. Be careful when puréeing hot liquids—don't fill the blender more than 2/3 full and hold the lid down firmly when you turn the blender on. Pass the puréed soup through a fine-meshed sieve, pressing firmly upon the solids with a ladle or spatula in order to extract as much liquid as possible.

Return the soup to the pot. Add the heavy cream and gently heat through.

While the soup heats, run the goat cheese crostini under the broiler briefly to soften the cheese. Sprinkle the warm cheese with minced chives.

Divide the soup among warmed soup bowls and float a goat cheese crostini in the center of each bowl. Sprinkle the soup with more chives and drizzle a bit of olive oil over the soup. Pass extra goat cheese crostini separately.

Makes 2 quarts.