COMBINE THE FILLING ingredients and mix them together well. Spoon a generous portion of filling onto each wonton skin. Bring up the sides and press them around the filling mixture. Tap the dumpling on the bottom to make a flat base. The top should be wide open, exposing the meat filling. Set up a steamer or put a rack inside a wok or large deep pot. Pour in about 5 cm of water and bring it to a boil. Put the dumplings on a plate and place this into the steamer or onto the rack. Cover the pot tightly, turn the heat to low and steam gently for about 20 minutes. (You may have to do this in several batches.) Serve the dumplings hot with soy sauce to dip.