Start by marinating your chicken. 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.

Next, prepare the sauce mixture. 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.

Place your 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 80-90% done, but you’ll cook it again at the end.

Without washing the wok, turn on the heat to medium. Add another tablespoon of oil, along with the garlic and onion. Stir-fry for 20 seconds, then add the Shaoxing wine around the perimeter of the wok.

Add the peppers and celery, along with the 1 teaspoon black pepper. Stir-fry for another 30 seconds.

Pour in the sauce mixture. Use your wok spatula to stir the sauce around the sides of the wok to deglaze, and let it come to a simmer.

Stir up the cornstarch and water slurry, and drizzle the mixture into sauce while stirring constantly. Allow the sauce to 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.

At this point, you can make adjustments. If you like your brown sauce darker, add a dash more of dark soy sauce. Add more cornstarch slurry if your sauce is too thin, or more chicken stock or water if the sauce is too thick. Serve with steamed rice.