PreparationTo make the pork filling: If the pork is not finely ground, mince well with a knife. Place the pork in a large bowl and cover. Bring a large pot of water to boil over high heat. Add the cabbage; blanch until just wilted. Using a slotted spoon, remove cabbage to strainer set over a large bowl. Press down on cabbage to squeeze out all liquid. Transfer to cutting board; roughly dice. Meanwhile, place grated ginger in a small bowl; cover with water and let steep for a few minutes. Slice scallions lengthwise, then thinly slice. You should have a good mixture of white, light green, and dark green pieces. Add to the bowl with the pork. Place a strainer over the pork bowl; strain the ginger so that the juices are added to the bowl. Press down on ginger to squeeze out all juices. Discard ginger left in strainer. Add the soy sauce, cooking wine, sesame oil, salt, and pepper to the meat mixture. Stir in chopped cabbage until completely incorporated. To make the wrappers: Place the flour and salt in a large bowl. Slowly add water and mix with your hands. Knead the mixture until it forms a soft dough. Place the dough on a lightly floured counter and knead until very smooth. Divide dough into 50 small, equal pieces. Flatten each piece with your hand to form a thin, round pancake, approximately 3 inches in diameter. The center should be slightly thicker than the edges. To wrap the dumplings: Using a spoon or chopsticks, place one heaping tablespoon of dumpling filling in the center of the dumpling wrapper. Using your fingertip, wet the outer edge of the dumpling wrapper with water. Fold up the sides of the dumpling into a half-moon shape. While holding the dumpling lengthwise, curved side up, use your index finger and thumb to pinch the edges of the dough on one side of the dumpling into "pleats," pressing each pleat against the flat side of the dough to seal the dumpling as you go. Start at one corner of the dumpling and work your way to the center (making three to four "pleats"). Then work from the other corner to the center creating another three to four "pleats." Firmly press the pleated side of the wrapper against the flat side to be sure the dumpling is completely sealed. If there is to much filling and the dumpling cannot be sealed, remove the extra filling to prevent leakage during cooking. Line up the finished dumplings on a foil-lined cookie sheet to prevent them from sticking. You can freeze dumplings this way for up to one month. To cook: To cook the dumplings, gently lower them into a medium pot of boiling water and boil for approximately three to five minutes. They are done when the dumpling skins are translucent and the dumplings have been floating for about three minutes. Remove from pot carefully with a slotted spoon. Serve hot. For Dipping Sauce: Mix the ingredients for the sauce in a small bowl and serve on the side.