Add diced chicken, 1 ½ teaspoon cornstarch, 2 tablespoons soy sauce, 2 teaspoons sesame oil, and black pepper to a medium-sized bowl, mix to combine. Allow chicken to marinate while preparing the other ingredients.
To make the sauce, whisk together 3 tablespoons water, 3 tablespoons soy sauce, 3 tablespoons rice vinegar, 3 tablespoons honey, and 1 tablespoon sesame oil in a medium-sized bowl.
Make a cornstarch slurry by whisking together 1 teaspoon cornstarch and 2 teaspoons water.
Heat a wok or large saute pan over medium-high heat. Add vegetable oil, once the oil is hot add the marinated chicken in a single layer in the pan.
Allow it to cook without moving for 2 minutes. Stir and cook for 2 minutes then transfer to a clean bowl.
Turn heat down to medium and add the onions, stir-fry for 1 minute.
Add the bell peppers and stir-fry for 1 minute.
Add the garlic, ginger, and chili peppers, and cook for 1 minute.
Add the chicken back to the pan. Add the sauce to the pan and allow to heat and bubble, 1 to 2 minutes.
Mix the cornstarch slurry and then gradually add to the pan, stirring to combine. Stir and cook until the sauce is thickened, 1 minute.