Melt butter on top of a double boiler, add flour and cook until the flour just starts to turn golden. Add milk and cook, stirring with a wire whisk, until the sauce is thick and smooth. Add grated Parmesan, salt, cayenne pepper, and grated nutmeg to taste. Saute finely chopped shallot in butter until transparent, add sliced mushrooms, and cook until all moisture has evaporated. Add mushrooms to sauce. Beat egg yolks until frothy, fold into sauce mixture. Beat egg whites until they are stiff, but not dry, and fold into mixture. Pour into a buttered souffle dish and bake at 350 F for about 40 minutes.{$7e}(Original recipe for 4)
