In a mixing bowl, add the Marinade ingredients.
Mix together with your hands, let the chicken marinate for 15-30 minutes.
While the chicken is marinating, prepare the onion and peppers. I only had one bell pepper so I sliced up some Shiitake mushrooms.
In another bowl, whisk together the oyster sauce, light soy sauce, water, black pepper, and 1 tablespoon of the cornstarch. Set this aside.
After the chicken has marinated, add the remaining 2 tablespoons of cornstarch. Use a spoon and mix together to coat the chicken all over.
Heat a large non stick pan with 2 tablespoons of oil, on medium high heat. Add the chicken.
Stir fry for about 5 minutes, then remove the chicken from the pan and set aside.
Add the last tablespoon oil and when hot, add the onions and peppers, stir fry for a few minutes and the colors will brighten. Add the ginger and garlic and stir fry for another minute.
Return the chicken to the pan, give the sauce another quick whisk then stir that into the pan. Stir fry to coat the chicken well and the sauce thickens. Remove from heat.
Serve with rice or vegetables of your choice on the side.