Method
1. Between two sheets of parchment, tenderise the beef by bashing with a tenderiser or rolling pin.
2. In a dish, stir the marinade ingredients together. Add the beef, toss to coat and leave to marinate for several hours in the fridge.
3. Heat a large heavy based frying pan over a high heat. Pat the steaks dry. Heat 1 tbsp of oil in the pan. Add the steaks to the pan, allow to sear for 1 minute, flip over, cook for 30 seconds. Add the butter, cook for 30 seconds more. Transfer the steaks to a dish to rest, covered. Add the rest of the marinade to the pan to deglaze the pan. Reduce the sauce for 1 minute.
4. Heat the remaining oil in a wok, stir-fry the mushrooms for 1-2 minutes, add the greens then stir through the reduced sauce.
4. Serve the steaks with the rice and greens.