I found this recipe on Weibo.
Soy sauce 30g
Oyster sauce 20g
Tomato sauce 18g
Cooking wine 18g
Minced garlic 10g
1. Mix all the ingredients above in a bowl.
2. Put half chicken in a plastic bag. Then pour the sauce into the bag.
3. Gently massage the chicken to let it be coated with sauce. ( I poked the chicken several times with a toothpick before this step.)
4. Let the chicken stay in sauce bag for hours. Or you can put it in the fridge for overnight.
5. Preheat oven to 180 degree C. Wipe the chicken with kitchen towel. Original recipe said to brush butter onto chicken, but I used olive oil instead. And also sprinkle some black pepper.
6. Put chicken on grilled and roast for 40 mins. If you want the color to be darker. You can turn to 220 degree at the last 5-10 mins.