Thaw the duck, if frozen. Remove any excess fat, and rinse and pat dry with paper towels. Rub the entire surface of the duck, inside and out, with the salt. Cover and refrigerate for several hours or, even better, overnight
Put the scallion in the cavity and lay the slices of ginger on top of the duck. Add at least 2 inches of water to a large flameproof roasting pan with a lid and put the pan on the stove
Place a large rack in the roasting pan and bring the water to a boil. Choose an oval casserole large enough to hold the duck and small enough to fit into the roasting pan
Place the duck in the casserole and then put the casserole on the rack. Cover and steam for 1 hour, checking the water level from time to time and adding more boiling water if necessary. Save the duck broth to use in soups or stir fry dishes. When done, remove the duck from the casserole and place it on a rack to dry
Combine the ingredients for the glaze in a small saucepan and bring to a boil. With a pastry brush, paint the hot glaze over the surface of the duck. Allow duck to dry for 1 hour
Preheat the oven to 375_ F. Roast the duck, breast side down, for 20 minutes. Turn over and continue to roast for 40 more minutes.
Transfer duck to a chopping board and allow to cool slightly. Using a cleaver, disjoint and cut the duck through the bone into bitesize pieces. Arrange the pieces on a serving platter, garnish with coriander and serve.
