In a bowl, toss the chicken with salt, pepper, and cornstarch until evenly coated.
Heat 1 tablespoon of oil in a large skillet or wok over medium-high heat.
Add the chicken and cook until golden and cooked through, about 5-6 minutes. Remove and set aside.
In the same pan, add the remaining oil. Sauté bell peppers and onion for 2-3 minutes until slightly tender.
Add garlic and ginger; stir-fry for another 30 seconds until fragrant.
Return the chicken to the pan.
In a small bowl, mix black pepper, soy sauce, oyster sauce, Shaoxing wine, sugar, and water.
Pour the sauce into the skillet and stir everything together until well-coated and heated through.
Serve hot over steamed rice.