Combine beef, soy sauce, cooking wine, Sesame oil, and ground black pepper. Mix well.
Add cornstarch to the mixture. Continue to mix until all the ingredients are well blended. Set aside.
Heat 3 tablespoons of cooking oil in a pan or wok. Once the oil gets hot, stir-fry the beef slices for 4 to 6 minutes or until the beef turns brown. Remove the stir fried beef from the pan and place in a clean plate.
Using the same pan, add the remaining cooking oil. Add the bitter gourd (ampalaya) slices and stir-fry for 2 minutes.
Pour-in the oyster sauce. Continue to stir-fry for 30 seconds.
Add the stir-fried beef. Cook for 1 minute more.
Transfer to a serving plate. Serve with warm rice.
Share and enjoy!