Bring the steaks to room temperature. Drizzle them with oil, then rub it into both sides. Heat the frying pan over a high flame to very hot. Add the steaks and cook for 2-3 minutes, until crusty and golden underneath.
Turn over and cook until golden underneath once more. Add the butter to the pan, shaking it a little to distribute. Standing well back from the pan, add the cognac. It wil