Stir-Fried Beef with Black Bean and Chilli

Name: Stir-Fried Beef with Black Bean and Chilli (Jia Chang Niu Rou 家常牛肉)
Cuisine: Chinese
Ingredients: 1 tsp light soy sauce; 1 tsp Shaoxing wine; 1½ tsp potato flour; 300 g lean beef steak; ½ tsp dark soy sauce; 1 tsp sesame oil; Salt; 2½ tbsp Laoganma black bean sauce; 3 tbsp cooking oil; Small bunch of coriander (about 40 g); ¼ green pepper; ¼ red pepper