Place a non-stick pan onto medium heat, and add the oil. Once the oil is smoking hot, sprinkle the salt and pepper all over the steak on both sides, then gently place the steak in the pan. Make sure the steak is well caramelized on one side, then turn it over, cook for a further 2-3 minutes on all sides. Place in hot barbecue grill, keep checking it every 5 minutes, making sure that the steak is not on a direct heat otherwise the outside could burn, best to use a probe for this part, the optimal temperature for the steak is 52 degrees C in the middle of the meat. Take out of the grill and back on to the heat, add the butter and the aromatics, baste the foaming butter over the steak. Allow the steak to rest, for half of the time you cooked it. Slice, then season the steak once more.