Dice the beef into bite-sized cubes.

Heat a pan with a little oil and sauté 1 tbsp minced garlic with the diced beef.

Cook the beef until the surface loses its pink color.

Add diced vegetables (bell peppers, onions, chili peppers) to the pan.

Stir-fry the vegetables and beef over high heat.

Add 2 tbsp ketchup, 2 tbsp oyster sauce, and a pinch of black pepper. Stir well to coat evenly.