Parboil a sweetbread in Sherry wine twelve minutes. Drain, cool, cut in four pieces, and lard. Cook in frying-pan same as Sweetbreads à la Napoli. Peel mushroom caps, cover with Sherry wine, let stand one hour, drain, and sauté in butter. Arrange on circular pieces of toast, over each of which has been poured one teaspoon wine drained from mushroom caps, and season with salt and pepper. Pile five or six mushroom caps on each piece of sweetbread, add two tablespoons heavy cream, and bake in a moderate oven, eight minutes. Cook in individual glass-covered dishes.