1 Cook the steaks in the oven for 40 to 45 minutes. 2  The steak will still look fairly uncooked when you remove it from the oven. 3  A thermometer inserted into the thickest part of the steak will reveal a cooking temperature five to ten degrees lower than the desired doneness. Preheat the oven to 275 degrees. 2  Season the steaks with sea salt and fresh-cracked black pepper. 3  Place steak on a rack placed over a rimmed baking sheet and put in the preheated oven. 4  Cook the steaks in the oven for 40 to 45 minutes.