For the chicken:
Marinate the Chicken: In a bowl, combine the chicken pieces with 2 tablespoons of soy sauce and 1 tablespoon of cornstarch. Mix well to coat the chicken evenly. Let it marinate for about 15-30 minutes.
Prepare the Stir-Fry: Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Add the marinated chicken and stir-fry until it’s cooked through and starting to brown, about 5-7 minutes. Remove the chicken from the skillet and set aside.
Cook the Vegetables: In the same skillet, add another tablespoon of vegetable oil. Add the sliced bell pepper, onion, garlic, and ginger. Stir-fry for about 3-4 minutes until the vegetables are tender but still crisp.
Combine and Season: Return the cooked chicken to the skillet with the vegetables. Add ½ teaspoon of black pepper, along with 2 tablespoons of soy sauce and 1 tablespoon of oyster sauce (if using). Stir well to combine all the ingredients and heat through for another 2 minutes.
