Nail head of possum to a board, just a little larger than the possum. Skin it. Make paste of lard, salt, pepper and rub over entire possum. Fill cavity with onions, garlic, chopped parsley and celery leaves. Place possum and board on rack in roasting pan. Lay 5 strips of bacon across breast. Add water and mushrooms. Add water as needed. Surround the possum with sweet taters. Leave uncovered.
Bake in oven (300 to 350 degrees) until tender. Baste every 15 minutes. To determine when done, pull leg away from body. When done, throw away the possum and taters and eat the board.
