In a large bowl, mix together pork, egg, cornstarch, scallion, ginger, wine, sugar, salt and pepper. Add 4 tablespoons water, one tablespoon at a time, and mix in the same direction until the mixture forms a ball and sticks together.
Form into 8 meatballs.
Stir together Coating Mixture ingredients in a small bowl. Brush the meatballs all over with Coating Mixture.
Heat 4 tablespoons oil in wok or large pan. Brown meatballs on all sides. You may have to do this in batches. Remove meatballs and set aside. Clean wok.
Heat remaining oil in clean wok. Add garlic and stir fry a few seconds. Add napa cabbage pieces and saute 2 minutes until just softened. Place meatballs on top of napa cabbage. Pour in chicken broth. Bring to a boil, then reduce heat to a simmer and cook, covered for one hour.
Mix together cornstarch and 1 tablespoon water. Stir into sauce until slightly thickened.
This dish reheats well if you choose to make it ahead.