Pork Gyoza

Name: Pork Gyoza
Prep time: 1 h
Cook time: 8 min
Total time: 1 h 8 min
Cuisine: Japanese
Ingredients: 12 ounces ground pork; 0.25 head cabbage, shredded; 1 egg; 2 spring onions, sliced; 1 tablespoon soy sauce; 2 teaspoons sake; 2 teaspoons mirin; 2 teaspoons minced fresh ginger root; 40 gyoza wrappers, or as needed; 2 tablespoons vegetable oil; 0.5 cup water; 0.25 cup rice wine vinegar; 0.25 cup soy sauce