For sauce, stir together the water, sherry, soy sauce, cornstarch, red pepper, and black pepper. Set aside. Pour the 1 tablespoon oil into a large skillet. (Add more oil as necessary during cooking.) Preheat over medium-high heat. Stir-fry garlic and ginger in hot oil for 15 seconds. Add regular cabbage (if using) and green onions. Stir-fry for 1-1/2 to 2-1/2 minutes or until crisp-tender. Remove vegetables. Add the ground beef or pork; stir-fry for 2 to 3 minutes or until no pink remains. Drain off fat. Push meat from the center of the skillet. Stir sauce. Add sauce to the center of the skillet. Cook and stir until thickened and bubbly. Add cooked vegetables, mushrooms, and, if using, Chinese cabbage. Stir all ingredients together to coat with sauce. Cook and stir about 1 minute more or until heated through. Remove from skillet; cool.
In a wok or 3-quart saucepan heat 1-1/2 to 2 inches of cooking oil or shortening to 365 degree F.
Meanwhile, place the wonton wrapper with a point toward you. Spoon 2 teaspoons filling just below the center. Fold the bottom point over the filling. Then tuck it under the filling. Roll the wonton wrapper once to cover the filling, leaving about 1 inch unrolled at the top of the wrapper. Moisten the right hand corner of the wrapper with a little water. Grasp the right and left-hand corners of the wrapper. Bring these corners toward you, below the filling. Overlap the left-hand and right-hand corners. Press the corners together securely to seal.
Fry egg rolls or wontons, a few at a time, in hot oil for 1 to 2-1/2 minutes or until golden brown, turning once. Remove from oil. Drain on a wok rack or on paper towels. Keep warm in a 300 degree F oven while frying remaining food. Serve warm with Sweet-and-Sour Dipping Sauce, Chili Dipping Sauce, or Chinese Mustard Sauce. Makes 12 appetizer servings.