Whisk together the cornstarch and water in a mixing bowl. Add the chicken to the cornstarch mixture and toss a few times. Let chicken remain in the bowl until ready to cook,
Heat the oil over high heat in a skillet. Swirl to coat the surface evenly. Wait for the oil to get hot, then add the onion, garlic, and chilies. Briskly toss in pan until fragrant, about 20 seconds, then add the chicken. Stir-fry until the chicken begins to turn white, about 3 to 4 minutes. Add the fish sauce, oyster sauce, and chicken stock. Cook until meat is done, another 3 to 5 minutes. Toss the red bell pepper and basil into the stir- fry and remove from heat. Serve immediately with steamed rice.
source from: vietnameseportal