Marinating: Combine chopped onions, ginger slices, sherry and salt. Place chicken on platter, rub inside and out with onion mixture, and place onion and ginger inside chicken. Allow chicken to marinate for 1 hour. Rub ham with same marinade, reserve. Steaming: Steam chicken, breast-side up, for 25-30 minutes. At the same time, steam ham for 20 minutes. Chicken should still be firm but very moist when removed from steamer. Drain chicken and allow to cool until juices congeal. Chop Chinese-style into bite-size pieces. Start by cleaving chicken in half lengthwise through the breast. Remove legs, thighs, and wings; chop in pieces. Turn carcass, skin down; cleave in half parallel to breast; turn and chop in pieces. Carefully remove and discard bones. Slice ham in bite-size pieces to match chicken pieces. Organize in alternating strips on serving platter, in shape of a chicken if possible. Leave space around perimeter for vegetable. Blanching and Stir-frying Vegetable: Wash and remove tough skin of broccoli. Slice into spears with flowerette at tip of each spear. Blanch spears in salted water for 20 seconds. Heat peanut oil in wok until it begins to smoke; stir-fry broccoli until bright but still crisp. Sprinkle with fish sauce, toss briefly, then remove to serving platter with meat. Glazing Sauce: Heat stock and crushed rock sugar in sauce pan; stir while bringing to boil. Dribble in cornstarch paste to make a light sauce. Stir in cooked oil. Pour over meat. Serve.