Heat the wok over medium-high heat. Once it is hot, add 1 tablespoon of oil and swirl it around the wok. Immediately add the pork and spread out into a single layer. Let it fry undisturbed for about 30 seconds.
Stir-fry the pork, breaking up chunks of meat as you go, so the slivers are separated, until it turns pale, about 1 minute. Remove the meat from the wok and set it aside in a bowl; wipe out the wok.
Turn the heat down to medium and heat the wok again.
Add the remaining 1 tablespoon of oil to the wok. Add the minced ginger and garlic and stir-fry for a few seconds, until they are fragrant. Add the bell pepper and zhacai and stir-fry another 1–2 minutes, until the bell pepper is slightly wilted.
Add the pork back into the vegetable mixture, quickly mix everything together, then pour in the sauce and stir-fry everything together, mixing well, for 1 minute.
Add most of the scallion slices to the wok (reserving just a few for garnish) and stir-fry everything for a few seconds. Remove everything from the wok and serve it hot, garnished with remaining scallion.