In a convenient mixing bowl, place the sliced chicken and sprinkle with 1 tablespoon soy sauce and 1 tablespoon cornstarch. Leave it for about 10-15 minutes while cutting the vegetables. This helps retain the moisture in the chicken during stir-frying.
Preparation of stir-fry sauce
In a small bowl, add and mix soy sauce, oyster sauce, rice vinegar, honey (brown sugar), sesame oil, and cornstarch mixed with water/chicken broth. Keep aside.
Stir-frying the chicken
Warm up one tablespoon of vegetable oil in a substantial wok or skillet over medium-high heat. Then pour in the chicken and continue stir-frying for about 4-5 minutes until the chicken is golden brown and fully cooked. Remove the chicken from the wok and place it to the side..
Stir-fry the vegetables
In the same wok, add the other 1 table spoon of oil. Then, add the chopped garlic and ginger (if using) and stir for about thirty seconds. Then add sliced onions, bell peppers, broccoli and carrots. Stir fry for approximately 4-5 minutes or until vegetables are tender-crisp.
Combine and finish
After that, chicken is put back into the pan and stir - fry sauce is poured into the chicken and vegetables. Combine everything and viscosity of the sauce is increased after 2-3 minutes of stirring and much heating and coating the insides of the mixture with warmth.
Serve
When cooked, take from the fire and transfer in plates to serve. You may sprinkle with sesame seeds or green on top as you wish.