Using your hands, mix together the pork, scallions, ginger, egg, garlic, rice wine, 1 teaspoon soy sauce, sugar, 1 teaspoon salt, and white pepper in a medium bowl. Once everything is combined, from a height of about 6 inches, drop the ball of meat into the bottom of the bowl 25-30 times.
Divide the meat into 4 equal parts and use your hands to form them into meatballs, moving the meatballs quickly between your two hands to help compress the meat further.
Heat the sesame oil in a wok or large skillet over medium-high heat. Sear the meatballs until they’re golden brown on all sides, about 6-8 minutes. Remove and set aside.
Cut the bottom off the Napa cabbage and separate the leaves. Place 2-3 layers of leaves at the bottom of a medium sized heavy pot or Dutch oven. Place the meatballs in the center and then arrange the remaining leaves in between the meatballs and around the edges of the pot to form a sort of nest. Add chicken broth until the meatballs are just covered. Adding remaining 1 tablespoon of soy sauce and 1 teaspoon of salt to the broth.
Cover the pot and place over medium-high heat. As soon as the soup boils, reduce the heat to medium-low, so it’s simmering gently. Keep covered and cook for 1 hour.
Season broth further with salt, if desired. Serve with rice.