1. Deseed red sweet pepper, green sweet pepper and cut into strips.
2. Put soy sauce, sugar, Shao xing wine, a little water into beef, mix well, put in oil and mix well, marinate for 30 mins, then put in cornstarch and mix well.
3. Heat the oil, put in beef and stir fry until half cooked and take out.
4. Heat the oil with the same pan, put in red sweet pepper and green sweet pepper, stir fry for 3 mins, then put in salt and stir fry until mix well, finally put in beef and stir fry until mix well.