This section is from the book "A New Book Of Cookery", by Fannie Merritt Farmer. See also: How to Cook Everything: 2,000 Simple Recipes for Great Food.
Parboil one sweetbread, cool and cut in one-fourth-inch pieces. Clean and peel ten large mushrooms and cut in pieces. Put in a small pan and add one tablespoon butter, one teaspoon lemon juice, one-fourth teaspoon salt and a few grains pepper. Cover and cook fifteen minutes, stirring occasionally. Melt two tablespoons butter, add four tablespoons flour and stir until well blended; then pour on gradually, while stirring constantly, one cup chicken or brown stock. Bring to the boiling point, add sweetbreads, mushrooms and one tablespoon heavy cream. Again bring to the boiling point and season with one-half teaspoon salt and a few grains, each, pepper and paprika. Line patty-pans with puff paste, fill with mixture, cover with pastry tops, brush over with white of egg, slightly beaten, and bake in a moderate oven twenty-five minutes. Serve at once.
Parboil one pair sweetbreads, cool, trim and lard upper surface. Clean and peel twelve mushroom caps and cook in two tablespoons butter two minutes. Add one-fourth cup Sherry wine and cook five minutes.
Wash one-half cup butter, put in a mortar with three tablespoons mashed, boiled sweet potatoes, one-half teaspoon finely cut chives, and one shallot and one clove garlic, each, finely chopped. Work until thoroughly blended; then rub through a sieve. Season with salt and paprika. Cut bread in one-third-inch slices, cut in rounds, toast on one side and spread untoasted sides with prepared butter. Put in four individual baking dishes, over each put a piece of sweetbread, over sweetbread arrange mushroom caps and spread with remaining butter. Pour around heavy cream, allowing two tablespoons to each portion. Put on glass covers and bake in a moderate oven eight minutes.
Trim sweetbread and parboil in Sherry wine until plump, the time required being about one-half hour. Keep covered during the cooking, turning twice. Cool and cut in pieces. Put one and one-half tablespoons butter in frying pan, and when melted add one-half teaspoon beef extract. Cook sweetbread in mixture until glazed, turning frequently. Drain canned artichoke bottoms and reheat; then arrange on circular pieces of sauted bread. Place pieces of sweetbread on each and pour around Lucullus Sauce made by adding one cup chopped sauted mushrooms to one cup tomato sauce.