Follow these simple steps to create your amazing Black Pepper Chicken:

1. Marinate the Chicken: In a bowl, combine sliced chicken, soy sauce, oyster sauce, cornstarch, and black pepper. Mix well and let it marinate for 10-15 minutes.
2. Prepare the Vegetables: While the chicken is marinating, slice the bell peppers and onion. Mince the garlic and grate the ginger.
3. Heat the Oil: In a large skillet or wok, heat vegetable oil over medium-high heat until hot.
4. Cook the Chicken: Add the marinated chicken to the pan in a single layer. Cook for about 5-7 minutes or until browned and cooked through. Remove chicken and set aside.
5. Sauté the Vegetables: In the same skillet, add garlic and ginger. Sauté for about 30 seconds until fragrant, then add the onion and bell peppers. Cook for 3-4 minutes until tender.
6. Combine Chicken and Veggies: Return the chicken to the pan with the vegetables. Stir-fry for an additional 2 minutes to mix the flavors.
7. Adjust Seasoning: Taste and add salt if needed. You can also sprinkle more black pepper at this stage if you prefer it spicier.
8. Garnish and Serve: Transfer the dish to a serving platter and garnish with sliced green onions if desired.

These easy-to-follow steps will guide you in creating a dish that is not only incredibly flavorful but also visually appealing.