In a medium bowl, toss the cabbage with 2 tsp. salt and set aside for 30 minutes to shed moisture. Wring out in a clean kitchen towel to extract as much liquid as possable.
In a large bowl combine the cabbage with the pork, shrimp, scallions, garlic, Shaoxing, ginger, soy sauce, sesame oil, sugar, and 1/4 tsp. black pepper. Stir well until mixed. Refrigerate for at least 20 minutes