Bob Sargent is the chef at Flora, a restaurant in Arlington, Mass. He shares his recipe for wild mushroom soup below:
When I was in cooking school, I remember my instructor, Michel LeBorgne, telling us that when making a vegetable soup, we should use water as stock, to let the vegetable flavor come through. It wasn't what I expected from a French chef, since most recipes at that time called for chicken stock. The mirepoix, or seasoning vegetables used to flavor the water, provide the good flavor that I associate with so many savory dishes. The power of onions to make everything right is a true wonder! This recipe serves 8 to 10.
3 T. butter
1 large onion, diced
½ cup leek, diced
1 large carrot, peeled and diced
2 lbs. assorted wild mushrooms, cleaned and sliced (I usually use cepes and other boletes, hen-of-the-woods, and chicken mushrooms)
1 c. white wine
2 qts. Water (if using dried mushrooms, use strained liquid as part of water)
1 peeled, cubed starchy potato
6 sprigs each parsley and thyme, wrapped in cheesecloth with 5 bay leaves and ½ tsp. black peppercorns
1 c. heavy cream
salt and pepper to taste
1. Melt butter in 6-8 qt. saucepan. Add onions, leeks and carrots. Sweat over medium heat five to 10 minutes. Add mushrooms and cook another 10 minutes. Add wine and cook five minutes more.
2. Add potato and two quarts water to pan and bring to a boil. Add cheesecloth-wrapped herbs and simmer until potato is very soft, about 15 to 20 minutes.
3. Let cool a bit, remove herbs and puree in a food processor or blender or put through a food mill.
4. Reheat with 1 cup heavy cream. Season with salt and pepper.