To make this soup, you can use a Yunnan ceramic steam pot, a squat, rounded lidded vessel with an internal spout that allows steam to circulate but not escape. A heat-proof casserole works almost as well.
Blanch The Chicken for 3 minutes in a large pot of boiling water. Remove the chicken and rinse thoroughly in cold running water. Place the chicken pieces around the Yunnan pot or on a rack set into a heat-proof casserole. Sprinkle the chicken with the salt, and scatter the ginger pieces and scallions over the top. Pour in the chicken stock and rice wine or sherry. Cover and gently steam on stove for 2 hours, replenishing the hot water from time to time if needed. Remove the ginger and scallion pieces. With a spoon, skim off all the surface fat. Ladle the soup into a tureen, and pass the chicken on a platter with dipping sauces.