Remove any fat from the steaks and place in the freezer for about 20 minutes to make them easier to slice them into thin shreds against the grain.
Mix the sesame oil, rice wine/vinegar, soy sauce and corn flour into a shallow dish and then add the shredded steak. Mix up well and leave to marinate for 10 minutes out of the fridge.
Heat half the Sunflower oil in a frying pan or wok. Add the beef and stir-fry for about 3 minutes until browned. Remove with a slotted spoon and put on a plate and cover with foil to keep it warm.
Wipe the pan and add the remainder of the Sunflower oil. Heat through then add the onion, garlic and ginger. Fry for a minute taking care not to allow it burn then add the kale and chillies and stir fry for 2-3 minutes until the kale has wilted.
Return the beef to the pan and add the black bean sauce. Fry for a further minute and then serve with boiled or steamed white rice (Basmati is best)