2. Place a few wonton wrappers on your work surface. Place a spoonful of the mixture in the center of each wrapper. Gather the wrapper around the filling to form a beggar's purse shape leaving the top slightly open and place the finished dumplings on a baking sheet. Continue filling the wrappers until all the mixture is used.
(This can be made in advance and frozen. Freeze on a baking sheet or in a plastic container.)
3. Meanwhile, combine the soy sauce, sesame oil, ginger and red pepper flakes in a small bowl. Stir to combine and set aside.
4. Line a bamboo or metal steamer with cabbage or lettuce leaves. Place the dumplings on the leaves, without letting them touch. Set the steamer in a large saucepan over an inch of simmering water and cover. Steam until wrappers are translucent, about 12 to 15 minutes. Continue with all the dumplings. Transfer the dumplings to a serving platter and serve with the dipping sauce.