1. Trim the end of kailan.
2. Boil one pot of water, add in 1 tsp salt. Blanch kailan for 2-3 mins. I used baby kailan, so I just boil them for 2 mins.
3. Put beef slices in a bowl. Add in 1 1/2 tsp light soy sauce and 1 tablespoon corn starch. Mix them well.
4. Prepare other vegetables. 3 shiitake mushrooms, 1 small carrot, 2 green or red chili, 1 stalk leek. Chop them into small size.
5. Heat oil in the pan. Put marinated beef slices in. Quickly stir to separate slices apart. When the beef turns no more pinkish, take them out and set aside.
6. Add in 1 tablespoon oil if needed. Sauté a little chopped ginger. When aromatic, add in carrot and Shiitake mushroom. Stir fry for 2-3 mins.
7. Add beef back in the pan. Stir fry for 1 min.
8. Add in 1 tsp sweet cooking wine, 1/2 tsp light soy sauce, 1 1/2 tsp oyster sauce. Stir fry evenly.
9. Put in chili and leek. Stir fry for another minute.
Spread kailan in the plate. Put beef over kailan.