Take a stale loaf of white bread and cut slices as you would for toasting. Fry these quite crisp in butter. Prepare a rather stiff Béchamel sauce (not forgetting a little grated nutmeg), add to it two or three mushrooms cut in thin pieces and previously cooked, mix well, season with salt, pepper and a little Cayenne pepper; spread the mixture thickly on the pieces of fried bread. When these little croûtes, or fritters, are cold, coat them with beaten egg, sprinkle with bread-crumbs and fry in deep fat or oil. Serve very hot.