Take several young lettuces, wash them and remove their wilted leaves, tie the tops together, and lay the lettuces side by side in a baking-pan and pour in one and one-half inches of stock.
Cover the pan, and put it in a moderate oven for one-half an hour, adding stock when necessary.
Place a fork under the middle of each lettuce, raise and drain, and lay them doubled up on a hot dish.
Season the gravy in the pan with butter, salt, and pepper, thicken with one beaten egg, and pour it over the lettuce.
Serve hot.