Cut the steaks into 1cm thick strips and toss in the cornflour and some seasoning.
Pre-heat the BBQ for 2-3 minutes and add a drizzle of the sesame oil. Add the steak and fry for 3 minutes then remove with a slotted spoon and set aside. Add the onion and pepper to the pan and fry for 5 minutes until just starting to soften then add in the garlic and ginger. Give it a good mix and cook for just a minute then add the beef back to the pan along with the spring onions. Stir through the black bean sauce, vinegar, sugar and a splash of water to loosen the sauce. Bring to a simmer then remove the pan from the heat.
Serve with sticky rice in deep bowls.