Step 1

In a large bowl, combine beef with beef marinade ingredients. Mix well and set aside to marinate for 15 minutes.

Step 2

In a medium-sized bowl, combine all black pepper sauce ingredients. Mix well until the cornflour has dissolved. Set aside.

Step 3

Add oil to a large, preheated wok or frying pan over high heat. Swirl the wok in a circular motion until well coated with oil.

Step 4

Once the wok is very hot (note 2), add marinated beef cubes and spread it out into a single layer. Sizzle over high heat for ~45 seconds without flipping. So no touching! With a spatula, flip the beef over and sizzle the other side for 45 seconds. Then, remove the beef into a bowl and set aside. (note 3)

Step 5

In the same wok (no need to wash), add capsicums, onion and garlic. Stir fry over high heat for ~2 minutes. Add beef back into the wok along with all the juices. Stir fry for about 15 seconds. (note 4)

Step 6

With a small spoon, mix the black pepper sauce again (the cornflour would have settled to the bottom of the bowl). Pour the sauce into the wok and add spring onions. Stir fry for a final 30 seconds until the sauce is glossy and thick.