Cream Of Mushroom Soup Ingredients 3 tablespoons unsalted butter 2 tablespoons olive oil 3/4 cups finely chopped shallots 2 pounds white cultivated mushrooms - thinly sliced 1 teaspoon fresh thyme leaves salt and freshly ground black pepper 1/3 cup cream sherry 3 tablespoons all-purpose flour 3 1/2 cups low-salt chicken broth - reserving 1/2 cup 1/2 cup milk ground nutmeg to taste - about 1/4 teaspoon 1/2 cup sour cream In a large saucepan melt butter with the olive oil over moderate heat. Add the shallots and cook until tender, about 2 to 3 minutes. Add the sliced mushrooms, thyme leaves, salt and pepper, cooking until all of the liquid rendered from the mushrooms evaporates. Add the Sherry and cook until evaporated. Remove a 1/2 cup of the cooked mushrooms and reserve. Stir in the flour and cook for 2 to 3 minutes.  Add 3 cups of the chicken broth, bring to a simmer and cook for 15 minutes. In a blender puree the soup in batches until smooth. For a very smooth soup, pass through a fine sieve. Return soup to saucepan, bring to a simmer and whisk in the milk. Add reserved chicken broth to achieve desired consistency. Adjust seasoning with salt, pepper and nutmeg. Lower heat and whisk in 1/4 cup of the sour cream. Keep soup warm but do not simmer or boil. Serve soup garnished with reserved cooked mushrooms and a dollop of the remaining sour cream.