Season beef with salt and pepper. Fry up the beef till brown. Set aside. (You may put it in the fridge/freezer to assemble at a later time)

At the time of meal, heat up pan with some oil, add onion and green pepper. Stir fry the veggies till onion is translucent.

Add beef and garlic. Stir fry till fragrant.

Add soy sauce, salt and pepper to taste. Stir fry till fragrant.

Mix corn flour with a tablespoon of water. Lower heat for the stir fry, corn flour mixture to the stir fry. Stir fry till sauce is thickened.