Marinate the Pork: In a bowl, combine the thinly sliced pork with salt, cooking wine, oyster sauce, water (or chicken stock), white pepper, and cornstarch. Mix well until the pork is evenly coated. Add ½ tablespoon of vegetable oil to the marinated pork and mix again. This helps to keep the pork slices from sticking together during cooking. Let the pork marinate for at least 10 minutes while you prepare the other ingredients.

Prepare the Ingredients: Slice the ginger and garlic. Cut the shiitake mushrooms into slices after removing their roots. Chop the scallions, keeping the white parts and green parts separated.

Stir-Fry the Pork: Heat a wok or large skillet over medium-high heat and add enough cooking oil to coat the bottom. Add the marinated pork slices in a single layer and stir-fry for about 2-3 minutes until they are no longer pink and slightly browned.

Sauté the Aromatics: Add the sliced ginger and garlic, and stir-fry for 30 seconds until fragrant. Add the white parts of the scallions and stir-fry for another minute.

Cook the Mushrooms: Add the sliced shiitake mushrooms to the wok and stir-fry for about 2-3 minutes until they become soft and release their juices.

Combine and Season: Add the oyster sauce and light soy sauce, and stir well to coat all the ingredients evenly. If using, drizzle with sesame oil for added fragrance and flavor.

Finish and Serve: Add the green parts of the scallions and stir everything together for another 30 seconds. Transfer the stir-fry to a serving plate and garnish with more green onions if desired. Serve hot with steamed rice or your choice of noodles.