Marinate the Chicken: In a mixing bowl, combine the chicken with salt (if using), cooking wine, oyster sauce, water or chicken stock, white pepper, and cornstarch. Mix well to coat evenly, then add the vegetable oil and mix again. Set aside for 15 minutes to marinate.

Prepare the Stir Fry Ingredients: Peel and thinly slice the ginger and garlic. Chop the shiitake mushrooms into thin slices and separate the scallions into their white and green parts, setting them aside for later use.

Cook the Chicken: Heat a wok or large skillet over medium-high heat and add a drizzle of cooking oil. Stir-fry the marinated chicken until it turns golden brown and is cooked through, about 3–4 minutes. Remove from the wok and set aside.

Sauté Aromatics and Mushrooms: If necessary, drizzle in extra oil and heat it up. Once hot, toss in the ginger and garlic, sautéing until they release a fragrant aroma. Add the white parts of the scallions and shiitake mushrooms, stir-frying for 2-3 minutes until the mushrooms soften and become tender.

Combine and Finish: Return the chicken to the wok, add the oyster sauce and light soy sauce, and stir to coat all ingredients evenly. Cook for another 1–2 minutes. Drizzle with sesame oil (if using) and toss in the green parts of the scallions.

Serve and Enjoy: Transfer the stir fry to a serving plate and pair it with steamed rice or noodles.