In a small bowl, combine the ground pork, soy sauce, and 1 teaspoon cornstarch. Mix well and marinate for at least 10 minutes.
1 pound ground pork breakfast sausage, 1 ½ tablespoons soy sauce, 1 teaspoon cornstarch
Shred the cabbage and carrots using a food processor or by hand. Thinly slice the shiitake mushrooms or pulse them in a food processor until finely diced.
8 cups Napa cabbage, 1 cup carrot, 6 fresh shiitake mushrooms
Heat a wok or large sauté pan over high heat. Add 1 tablespoon soybean oil and swirl to coat the surface.
Add the marinated pork and stir-fry until no longer pink, about 2–3 minutes.
Lower the heat to medium-low and push the pork to one side of the pan.
Add the garlic, cabbage, carrots, green onions, ginger, mushrooms, and water chestnuts to the empty side of the pan. Stir-fry for about 1 minute until vegetables are slightly softened.
8 cups Napa cabbage, 1 cup carrot, 3 green onions, 2 cloves garlic, 1 teaspoon fresh ginger, 6 fresh shiitake mushrooms, 1 (8-ounce) can diced water chestnuts
Stir in the rice wine, additional soy sauce if needed, sugar, sesame oil, and black pepper. Continue stir-frying for another minute.
1 tablespoon rice wine, 2 teaspoons sesame oil, 1 tablespoon soybean oil, ½ teaspoon black pepper
Strain filling using a colander over a mixing bowl to remove excess juices and then transfer the filling to a baking sheet and spread it out.
Allow the filling to cool for 15 minutes.