Mix all the dough ingredients in a bowl and set aside for half an hour. Roll the dough to a thickness of 0.039 inches (1 mm). You can use a pasta machine for accuracy. Cut circles with a glass (about 2.75 inches/7 cm) and sprinkle a lot of flour on the dough circles to prevent them from sticking to each other.
Heat oil in a pan and fry the gyoza for about 2 minutes. Add water, cover with a lid, and cook until the water evaporates.