In a bowl, marinate beef with all the sauce and slices. Set aside for 30 mins.

Heat a frying pan over medium high heat, add 2 tbsp cooking oil and beef. Cook for 1-2 mins. Transfer to a plate.

Cook with the same pan, add in bell peppers, cook for 2-3 mins.

Put back the beef and toss for a minute or 2. ( Add salt if needed)

Transfer to a serving plate, sprinkle chopped coriander (optional)