Take some wheat flour and mix it with some water. Roll the mixture into very thin dough skins, about the thickness of a sheet of thick paper, about 2 1/2 inches across.
The traditional Jiao-zi stuffing calls for equal portions of very finely chopped pork and Chinese cabbage with some green onions and a pinch of salt. Actually you can put most anything in the stuffing. I like to add fresh green beans, and diced carrots give a nice crunchy quality. Put the filling in the middle of the dough skins. Pinch the edges of the skins together (a few drops of water along the edges will help if they won't stick together.) Put the Jiao-zi in a colander and place them in gently boiling water. About 10 minutes later, when they are all floating, take them out of the water, season to taste with soy sauce and vinegar, and serve them.
Their potstickers cousins are made in exactly the same way, though it is better to make thicker skins. Instead of boiling them, fry them in a medium sized skillet. Fill the bottom of the skillet with cooking oil and heat it until it is nearly smoking. Brown the potstickers on the bottom, add one cup of hot water, cover and cook until the water has evaporated. Take off the lid, and with a swift motion of the wrist, empty the skillet upside down onto a heated serving plate.
It is usually at this point that you learn why this dish is called "potstickers." But they taste really good, and you'll feel a great sense of accomplishment when you can get them out whole. After while you can start working on artistic appearance.