Pull your tomahawk steak out of the refrigerator 1 hour prior to grilling. Set aside on counter.
Preheat your grill to 225 degrees F. I used my Traeger for this recipe but any grill will suffice.
Pat the steak dry with paper towels. Season both sides with salt. I don't like black pepper but feel free to use it if you do. If you do want pepper on it I suggest waiting till you slice it after it's cooked.
Transfer the tomahawk steak to the preheated grill. Put it on the grates and insert your meat probe. Close the lid and leave the steak on the grill, undisturbed until it reaches an internal temperature of about 115 - 120 degrees F. In theory this should take about 45 to 55 minutes, but every grill is different. That is why a meat thermometer is so important when grilling.
Remove the steak from the grill and place it on a plate or cutting board. Tent it with aluminum foil and let it rest for about 10 minutes or so.
While the steak is resting, crank your grill up to about 450 degrees F.
Side note: At this time you should decide if you're going to sear the steak in a cast iron pan or directly on the grill grates. I did one side of mine in a cast iron pan and the other side directly on the grill to see if I noticed a huge difference. I didn't. Both sides were delicious!
Place the steak on the grill directly or in a cast iron pan on the grill and sear all sides for about 1 minute or so. More if you like more char.
Remove the steak from the grill and place it on a cutting board.
In a small pan, warm up the butter on the grill. A cast iron pan works perfectly. Once the butter bubbles toss in the garlic. Cook for about 1 minute, or until garlic becomes fragrant. Remove from grill carefully.
You can leave the garlic in the butter or strain the pieces out. Either way works.
Carve the steak then pour butter over top.
Serve!