Cut the beef into small slices and place in a bowl
Add the oyster sauce, seasoning sauce and cooking wine
Mix together in the bowl using your hand
Cover with cling film and leave to marinate for 1 - 2 hours
Peel the garlic and dice into small pieces
Cut the red and green peppers into small chunks
Cut the spring onions and onion into small pieces
Heat your wok and add a small amount of cooking oil
Stir-fry the garlic until it begins to change colour
Add the black pepper and continue to stir fry
Add the marinated beef and continue to stir fry
Add the sugar and continue to stir fry
Add the peppers, onion and spring onions
Continue to stir until the peppers begin to soften up