Wash twelve large mushrooms. Remove stems, chop finely, and peel caps. Melt three tablespoons butter, add one-half tablespoon finely chopped shallot and chopped stems, then cook ten minutes. Add one and one-half tablespoons flour, chicken stock to moisten, a slight grating of nutmeg, one-half teaspoon finely chopped parsley, and salt and pepper to taste. Cool, fill caps, well rounding over top, cover with buttered cracker crumbs, and bake fifteen minutes in a hot oven.