1. Heat a cast iron skillet to high.
2. Season the steak with salt and pepper on both sides.
3. Sear the steak for one minute on each side.
4. Add half the butter to the skillet, and baste the steak for one minute, taking the skillet off the heat every 15 seconds so that the butter doesn't burn.
5. Flip the steak, and baste it with the remaining butter.
6. Let cool for about ten minutes.