Sprinkle cabbage with the 1/2 tablespoon of salt and let stand for 30 minutes. Place the cabbage on a clean dish towel or cheese cloth and squeeze out any water. The dryer the cabbage, the better. In a hot wok that's been coated with canola oil add the ground pork. Stir-fry until nearly cooked through. Add ginger, garlic and salt; cook for another two minutes. Deglaze with soy sauce, add napa cabbage and sesame oil, continue cooking until the cabbage is wilted. Check seasoning.
Plating: Spoon contents of wok over the tofu on a large serving platter, serve family style.