Marinade: In a bowl, add the sliced chicken, water, cornstarch, oil, oyster sauce, and black pepper. Rub the marinade ingredients into the chicken with your hands until the chicken has absorbed all the liquid. Set aside for 10 minutes.

Sauce: In a small bowl or measuring cup, add the chicken stock, oyster sauce, light soy sauce, sugar, dark soy sauce, and sesame oil. Stir everything together until well-combined, and set aside.

Heat wok over high heat until smoking. Add 2 tablespoons of oil, and then add the chicken all in a single layer. Sear the chicken until opaque on all sides (this should only take a couple minutes). Turn off the heat, remove the chicken from the wok, and set aside. The chicken will be near done, but youll cook it again at the end.

Without washing the wok, turn on the heat to medium. Add the onions, peppers and celery. Stir-fry for another 30 seconds. Add garlic and ginger. Saute another 30 seconds. Add the Shaoxing wine around the perimeter of the wok.

Pour in the sauce. Use spatula to stir sauce around the sides of the wok to deglaze, and simmer. Drizzle cornstarch slurry into sauce while stirring constantly. Simmer for 10 to 15 seconds until thick and gravy-like. Toss in the chicken and its juices. Stir-fry until the chicken is coated in the sauce and the sauce is thickened to your liking.