1. Prepare beef slices. You can buy a chunk of beef and cut into slices or you can just buy beef slices like I did.
2. Place beef slices in a bowl. Add in 1 Tbsp oyster sauce, cooking wine 1 tbsp, black pepper 1/2 tsp, salt 1/4 tsp, baking soda 1/4 tsp, water 1 tablespoon. Mix them by hand evenly. Let them rest for 10 mins.
3. Add in 2 tablespoon corn starch and 2 tsp cooking oil. Mix well. Let them be marinated for 30 mins.
4. Prepare bitter gourd. Cut 1/2 big bitter gourd open. Remove the seed and white part. Cut them into medium slices.
5. Place bitter gourd slices in a bowl. Sprinkle 1 tsp salt. Rest for a while. Boil in hot water for 2 mins. Then soak in cold water and drain.
6. Heat a pan. Add in 1 tablespoon oil. Add beef in. Quickly separate them. Stir fry a bit. Add in 1 tablespoon light soy sauce, 1 tbsp cooking wine and 1 tsp oyster sauce. Stir fry evenly till no more red color. Set beef aside.
7. Heat pan again. Add in 1 tsp oil. Stir fry butter gourd. Add in 1 tablespoon sugar. Fry for 1 min. Add in beef to blend evenly.