Additional plum sauce for topping Preheat oven to 400 deg. Pat ducks inside and out with paper towels. Rub skin and cavity with salt, pepper, garlic and ginger; then stuff with garlic and ginger pieces, onion and celery. Place breast side up on rack in shallow pan and roast, pricking skin frequently, 20 minutes. Remove from oven and carefully pour ice water over ducks. Return to oven and roast, pricking skin frequently, 20 minutes longer. Turn and roast another 20 minutes. Combine plum and bean sauces. Remove ducks from oven and spread some of sauce over backs. Roast 15 minutes. Turn ducks breast side up, spread sauce over and roast another 30 minutes, basting occasionally. Let ducks cool, then refrigerate overnight. Using kitchen or poultry shears, cut ducks in half lengthwise. With boning knife, cut around joints and remove legs. Cut away at joints; remove meat and discard bones. Cut away carcass; discard bones. Lay boned duck flat and slice thinly. Leave legs whole. To serve: Brush duck with additional sauce and reheat to warm through. Serve with dish of plum sauce and Chinese pancakes.