Finely chop the Napa cabbage, green onions, ginger and garlic. If you have one, a food processor makes quick work of this. Place the chopped veggies in a bowl with the remaining ingredients and mix until everything is evenly combined.
Line a baking sheet with waxed paper. On a clean work surface, lightly brush the outer 4 edges of a wonton wrapper with water. Place 1 teaspoon of filling in the center of the wrapper and fold in half to make a triangle. Carefully press out the air surrounding the filling and pinch the edges closed to seal. Fold the bottom two corners inward and use a drop of water to seal them in place (see photos). Repeat with remaining wrappers and filling.
At this point, you have three choices, freeze to use later (you can also cook some now and freeze leftovers for later), pan fry, or use in soup:
To Freeze: Freeze dumplings, uncooked, in a single layer on a waxed paper-lined baking sheet. Once frozen, remove to a lidded freezer container or plastic storage bag. Cook frozen potstickers as outlined below.
To Pan Fry: Heat a small amount of vegetable or canola oil over medium-high heat in a skillet large enough to hold the amount you want to cook in a single layer with little room to spare. Add potstickers to skillet, taking care to avoid sputtering oil, and cook without moving for about 3 minutes or until bottoms are browned. Add 1/2-cup water to the hot skillet and immediately cover. Reduce heat to medium-low and let dumplings steam for about 4 minutes or until cooked through. Remove from pan and serve with soy sauce for dipping.
To Use in Soup: Bring chicken stock to a simmer. Add desired number of dumplings to simmering stock and cook for about 5 minutes. Keep stock at a low simmer as opposed to a rolling boil in order to avoid the wontons coming apart. Optional wonton soup add-ins include cooked chicken, shrimp, boy choy and/or shitake mushrooms. A half-teaspoon or so of sesame oil stirred into the soup adds a nice flavor as well.