Salt the cabbage and toss. Rest 10 minutes, then squeeze out as much liquid as possible.
Combine pork, scallions, ginger, garlic, soy sauce, wine, sesame oil, cornstarch, and white pepper.
Fold in the squeezed cabbage. Stir vigorously until the filling looks sticky and cohesive.
Set up a wrapping station with wrappers, a small bowl of water, and a parchment-lined tray.
Place 1 tablespoon filling in a wrapper. Moisten the edge, then pleat and seal tightly. Repeat.
Heat 1 tablespoon oil in a nonstick skillet over medium-high. Arrange 10–12 dumplings flat-side down.
Pan-fry until the bottoms turn golden, 2–3 minutes. Add 1/4 cup water and cover immediately.
Steam until water evaporates, 4–5 minutes. Uncover and crisp bottoms 1–2 minutes more. Repeat with batches.
Whisk soy sauce, rice vinegar, chili oil, and sugar. Sprinkle with sesame seeds if using.
Serve dumplings hot with dipping sauce on the side.