In a medium bowl, combine the pork, green onions, cilantro, garlic, ginger, soy sauce and sesame oil and mix it all up with your hands.
To fill and shape wontons, set out a small dish of water, and working with one or two at a time, place a small spoonful of filling in the middle of each wrapper; moisten the edges with the water (dip your finger in) and fold over, pressing the edge tightly to seal. Pleat them on one side if you like, giving them a curved shape, or if you're using square wrappers, bring each point up to the middle and press to seal in an X shape. If you like, simply twist the top of dough to seal it closed - whatever works. (Try to push out any air bubbles as you seal them so that they don't float if you boil them or simmer them in soup.)
Place the dumplings seam side up on a baking sheet and if you like, cover with a tea towel to prevent them from drying out. (Dumplings can be prepared up to this point, covered with plastic wrap and refrigerated for up to 24 hours or frozen for up to six months. Transfer to freezer bags once frozen.)
To cook them as potstickers, heat a generous drizzle of canola oil in a large, heavy skillet set over medium-high heat. Place the dumplings close together in the pan and cook for a minute or two, until they're deep golden and crusty on the bottom. Don’t disturb them - they need to develop a nice golden crust.
Carefully pour about 1/3 cup stock or water into the pan (it will splatter), cover with a lid or foil, reduce heat to medium and cook for about 5 minutes to let them steam. Uncover and cook until the bottoms of the dumplings are very crisp and any excess liquid has evaporated. (Alternatively, boil the dumplings in water for 3-4 minutes, or toss directly into simmering soup.)
To make the dipping sauce, stir together all the ingredients and serve with the potstickers. If you used beef and boiled them, serve with peanut sauce instead, if you like. Makes about 2 1/2 dozen.