Cut the onion into chunks. Also, cut the yellow and red bell peppers into chunks. Place them in a plate and set aside.

Cut the beef ribs into chunks.

Add 1 tablespoon of salt, 1 tablespoon of cornstarch, an appropriate amount of white pepper powder, and an appropriate amount of cooking oil. Rub and marinate for ten minutes.

Mix 2 tablespoons of light soy sauce, 1/2 tablespoon of dark soy sauce, 1 tablespoon of cooking wine, 2 tablespoons of black pepper, 1 tablespoon of sugar, 1 tablespoon of cornstarch, and 4 tablespoons of water evenly.

Heat the oil in a pan, then add the beef ribs and fry until cooked.

Remove the beef ribs and set aside.

Add the onions and stir-fry until fragrant, then add the yellow and red bell peppers and stir-fry. Transfer to a plate and set aside.

Pour in the previously prepared sauce, add the beef ribs and yellow and red bell peppers.

Stir-fry a few times until the beef ribs and bell peppers are well-coated with the sauce, then serve.