Add the steak to a hot pan, the cook for 3 minutes. Turn as you regular way. Transfer out and cut the steak into cubes around 1.5 cm squares.
In another wok, add oil and then fry the garlic cloves until slightly browned on surface.
Place beef cubes and red onion in. Fry for another 1 minutes. Pour the sauce, add chopped green onion and mix well. Serve hot!