Marinate and cook meat from the ultimate pan-fried chicken recipe. Set aside.
Heat oil. Add garlic and saute till light golden. Add onion, followed by capsicum and carrot. Saute for about a minute.
Add soy sauce, vinegar, oyster sauce, tomato paste, tomato ketchup, salt, red chili flakes and white pepper. Mix together and cook for about 2 minutes.
Add water or chicken stock (about 1 – 1 ½ cups, as per preference). If using chicken stock, make sure to adjust salt accordingly. Bring the sauce to a boil, and add the cooked chicken. Let the sauce cook for a few minutes and let the chicken heat through.
Add cornflour, dissolved in water to the sauce and cook till it thickens.
Taste and adjust seasonings if required. Garnish with green onions, and serve hot with brown rice.