Every winter it seems I find a new favorite soup of the year and keep making it until everyone is sick of it. I do believe this is the one for this year. Let me just say this does not resemble Campbell's Cream of Mushroom Soup in the least.
Cream of Mushroom Soup
1 ounce dried wild mushrooms (porcini, cremini, or morels)
2 1/2 cups spring water (it does matter)
4 ounces (1 stick) unsalted butter, plus an additional 2 tablespoons, if needed
1 shallot, finely diced
8 ounces fresh button mushrooms, gently rinsed, patted dry with paper towels, and finely diced
7 tablespoons all-purpose flour
4 cups homemade chicken stock
2 cups heavy whipping cream
1/4 cup dry sherry
sea salt or kosher salt, to taste
freshly ground black pepper, to taste
Place the dried mushrooms in a large heatproof bowl. Bring the spring water to a boil and pour over the dried mushrooms. Allow to sit for 30 minutes. Remove the reconstituted mushrooms with a slotted spoon, pat dry, and chop finely. Set aside. Strain the mushroom water through cheesecloth and set the water aside. You should have about 2 cups of mushroom water.
In a large stockpot, melt the butter over low heat. Place the diced shallot and diced fresh mushrooms in the pot and allow to cook over low heat, stirring frequently, for about 10 minutes, or until soft. Raise the heat to medium, sprinkle in the flour, and stir constantly until the mixture bubbles and the flour is cooked, about 3 minutes. (If the mixture is completely dry, add up to 2 tablespoons of extra butter. Stir the mixture until the butter is completely melted, then stir and cook until the flour is cooked.)
Using a 1/2-cup measuring cup, add the chicken stock and reserved mushroom water 1/2 cup at a time. Bring the heat up to medium-high, and cook, stirring constantly, until the mixture thickens and bubbles. Lower the heat and add the chopped wild mushrooms, the cream, the sherry, and salt and pepper to taste. Cook, stirring frequently, for another 15 minutes. Remove from heat.
When the soup has cooled slightly, spoon it in batches into a blender, and puree. Place the pureed batches into a large heatproof bowl. When soup is completely pureed, pour it back into the stockpot, taste, and correct the seasoning. Bring the soup back to a simmer and serve.