Preheat the oven to 200°C, gas mark 6 and allow the steak to reach room temperature. Ensure the steak is lightly massaged with oil, sprinkled with salt & pepper. Heat a pan over a med/high heat until hot and sear the beef for 3-4 minutes on both sides, until browned all over Sear the sides briefly, then transfer to a roasting dish. Leave in the oven for 16 minutes for rare, 20 minutes for medium. Leave to rest for 10 minutes before serving.