1Soak mushrooms in a small bowl of warm water for 30 minutes. Drain, discarding the water. Cut away and discard the tough stems of the mushrooms, leave the cap intact.
2Place the venison roast in a heavy casserole just large enough to hold it snugly. To blanch the venison, add enough cold water to cover it by 2 inches and bring the water to a boil. Boil for 5 minutes. Transfer the venison to a colander and pour hot water over it. Discard the cooking water, wipe the pot clean, and replace the venison in the pot.
3Add the soy sauce, star anise, ginger, sugar, wine, scallions, and 2 cups of cold water. Bring to a boil and cover the pot. Reduce heat to low and simmer the meat for about 3 hours. Turn the meat over several times during the cooking period. When the meat is done, there should be about a cup of cooking liquid left over. If you have more, cook with pot off lid to reduce the sauce to one cup.
4The traditional serving method is to place the meat in a deep platter and pour the sauce over it. Decorate the cooked venison with the mushrooms. The venison should be soft enough to shred with a fork. Alternately, you may carve the meat into very thin slices and pour the sauce over this.
5If a main course, this will serve 8; if part of an appetizer tray or a larger Chinese meal, should serve about 12.