Remove the steak from the refrigerator to the countertop 45 minutes before turning the oven on to 225℉.
Place the cookie sheet with the steak on the rack into the oven to cook until the internal temperature is 105-110℉. This could take 1 hour 15 minutes to 1 hour 40 minutes.
Remove from the oven. 25 minutes before serving, turn the gas grill on high for 10 minutes.
Make sure the grill is hot, at least 550℉. Clean the grill, then season the grates with an oiled paper towel using tongs.
It's important to have everything ready, including your instant-read meat thermometer at the grill, before starting to sear the steaks. You need a watchful eye to calm the flare-ups. Start searing by placing the steak on the grill for 1 minute covered.
Flip the steak to the opposite side of the grill for 1 minute with the lid closed.
Flip the steak again to the opposite side for 1 minute, covered. Move the steak away from flare-ups.
Flip a fourth time to the opposite side of the grill and sear for 1 minute covered. Check the internal temperature. When their internal temperature is 126-130℉, pull the steaks off the grill back on the cooling rack over the cookie sheet. Their internal temperature will rise 5-8 degrees to a perfect medium rare.
Let the steaks rest on a cutting board for 10 minutes before carving. After resting, the meat will have a full pink color throughout, no purple.