Let the steaks sit at room temperature for about 30-60 minutes before cooking.
Preheat the oven to 220°C / 428°F. Pat dry the steaks with a paper towel before rubbing them with oil. Season with salt and pepper on both sides and set aside.
Heat a cast-iron skillet over high heat. Add butter to the hot skillet. Add the steak when it begins to smoke.
Sear the steak for about two minutes. Flip and sear another two minutes.
Add the minced garlic, more butter and fresh rosemary before transferring the steak to the preheated oven.
Cook until the steaks are the way you like them.
Transfer steaks to a plate or cutting board and let it rest for at least five minutes.