1. In a large bowl, mix together water chestnuts, scallions, shrimp, sesame oil, peanut oil, sherry wine, cornstarch, sugar, if desired, salt, and pepper.
2. Using a knife, trim the edges of each wonton wrapper to form a round. Place 1 tablespoon filling in the center of each wrapper; moisten edges with water. Cup your hand around wrapper, gathering folds up and around the filling. Press gathered folds lightly around filling to adhere.
3. Fill a large skillet or wok with 2 cups water; bring to a boil.
4. Set a bamboo steamer into skillet and line with a damp piece of cheesecloth or a piece of parchment paper. Place shau mai in steamer about 1-inch apart. Cover and cook until filling is cooked through, 6 to 8 minutes. Serve immediately with dipping sauce.

Makes 20.

Shau Mai Dipping Sauce [2]

1/3 cup unseasoned rice-wine vinegar
2 tablespoons freshly grated and peeled ginger

Mix together vinegar and ginger in a small bowl.

Makes enough for 20 shau mai.