Soak the dried mushrooms in a bowl of warm water for 20 minutes, or until they have softened. Squeeze out the excess water, cut the stems off the mushrooms, and thinly slice. Reserve 1 tablespoon of the mushroom soaking liquid.
Use a heavy cleaver to chop the chicken through the bone into bite-sized pieces. Place in a heatproof bowl and add the salt, pepper, soy sauce, rice wine or sherry, sugar, sesame oil, reserved mushroom liquid and cornstarch. Allow to marinate while bringing water to a boil for steaming.
Place the bowl on a rack in a pot for steaming or in a steamer such as a bamboo steamer in a wok. Place the chicken pieces in the middle of the plate and surround with the mushrooms. Sprinkle the shredded ginger and green onion over top. Steam the chicken over boiling water for 15 - 20 minutes, making sure it is thoroughly cooked. Serve over rice.