Take the steak out of the fridge 30 minutes before cooking to rest at room temperature.

Set your oven’s broiler to its highest setting (around 500°F) and let it heat for about 5 minutes. Adjust an oven rack so the steak will sit 3-5 inches below the broiling element.

Pat the steak dry with paper towels. Rub it with olive oil and sprinkle both sides evenly with salt, pepper, and garlic powder.

Place the steak on a broiler-safe pan or cast-iron skillet. Slide it under the broiler and cook for 5-6 minutes. Flip carefully, then cook the other side for another 4-5 minutes. Adjust the time based on how you like your steak.

Transfer the porterhouse to a clean plate tented with foil to rest. If desired, add butter to the top of the steak. Rest for 5 minutes before serving.