Salt the steak on both sides. Keep steak at room temperature for 45 minutes prior to cooking. About 10 minutes before you're ready to cook, preheat the oven to 275 degrees. Lightly spray a rimmed baking sheet with cooking spray
Heat a cast-iron skillet over high heat with butter or olive oil. Sprinkle steaks with pepper. Transfer steaks to the skillet and sear on each side for 3-5 minutes until a golden-brown crust forms, flipping just once
Transfer steak to baking sheet and place on the middle oven rack. Cook for 20-30 minutes, or until a digital thermometer reaches the temperature range for your desired doneness level using the chart above. Remove from oven
Rest on a foil-tented plate for 5-10 minutes. Check that the temperature of the thickest part of the steak reaches the range of your desired doneness level (130-135℉ for medium-rare)