Photo by Donna
Among the most exquisite foods are simplest foods. Creamy soup, here celery root soup, is a great example. I think we don’t make them even though they use the simplest of ingredients, don’t require chicken stock (or the travesty in a can masquerading as such), though you could certainly use chicken stock if you wished. The above soup is simply celery root and milk, thickened with a little roux, and enriched with a splash of cream. The velvet texture is the result of a fine mesh strainer (not strictly required to enjoy these soups but is the difference between a heavenly texture and an earthly texture).
What's also important to note is that this method can be used with just about any vegetable. Beets, cauliflower, parsnips, potato, mushroom, sweet bell pepper. Just about any green vegetable will work as well, though I prefer to use a light chicken stock for these. These soups can be served hot or cold. They can be made ahead and reheated. Seasoning can vary—a dash of curry in a mushroom soup, Parmigiano-Regianno in a cauliflour soup. Roast some cauliflower till it's well caramelized, and this soup and garnish become a great sauce for sauteed scallops, a la Jean Georges. There's no end to what you can do when you have a little technique. (The following recipe, is adapted from Ratio, where the technique is discussed in a little more depth.)
1-1/2 ounces flour (about 3 tablespoons)
1 ounce butter (2 tablespoon)
1/3 cup chopped onion
3 cups milk
1 pound celery root (or veg of your choice), 1/4 of it nicely diced, simmered or roasted till tender, cooled and reserved for garnish; the rest can be large diced or roughly chopped
3 ounces cream
salt to taste
fresh lemon juice or white wine vinegar to taste
Lightly cook flour and butter in your soup pot over medium heat. Add the onions and cook for another minute or two. Add the milk and simmer until it’s thickened, skimming any film that gathers on the surface. Salt it to taste. Add the chopped vegetable and cook gently until it’s tender, about fifteen minutes. Puree the soup in a blender, taste for seasoning and add more salt if necessary, strain it through a fine mesh strainer into a clean pan or serving dish, add the cream, season with lemon juice as necessary. Reheat the garnish in a microwave oven or in simmering water. Divide the garnish among the bowls, then pour in the soup (reheated as necessary).
For the vegetable garnish: Vegetable garnish can be cooked and cooled ahead of time, or while your soup is cooking as you would normally cook the vegetable. Most can be roasted or boiled, mushrooms and sweet bell peppers roasted or sautéed.