In a medium bowl, marinate the sliced chicken with soy sauce, oyster sauce, black pepper, and cornstarch. Let it sit for at least 20 minutes to absorb the flavors.
Heat vegetable oil in a large pan or wok over medium-high heat. Add the minced garlic and ginger, stirring quickly to avoid burning.
Once fragrant, add the marinated chicken to the pan. Stir-fry until the chicken is cooked through and golden brown, approximately 5-7 minutes. Remove from the pan and set aside.
In the same pan, add sliced mushrooms and bell peppers. Stir-fry for about 3-4 minutes until the vegetables are tender but still crisp.
Return the cooked chicken to the pan, toss everything together, and adjust seasoning with salt if necessary. Cook for an additional 2 minutes to heat through.
Finally, add in the chopped green onions and give it a quick stir before removing from heat.
Notes
Serve hot over a bed of steamed rice or noodles, garnished with extra black pepper and green onions.
Keyword black pepper, chicken, mushrooms, stir fry