Remove steak from fridge and dry brine. Remove the steak from the refrigerator and place on a flat cooling rack above a rimmed baking sheet. Season the steak liberally on all sides with the salt and let rest for 2 hours.
Preheat. Preheat your grill for two-zone cooking. You want half of your grill to be running on high, direct heat, and the other half no heat. The overall temperature of your grill should be around 275 degrees F.
Low temperature grill. Place the tomahawk steak on the indirect, low heat side and close the lid. Cook until the internal temperature reaches 120 degrees F for medium rare (45 minutes to 1 hour). Flip your steak once 20-25 minutes in.
High temperature sear. Move the tomahawk steak to the high, direct heat side of your grill and sear, leaving the lid open, for 3-4 minutes per side. Position the bone of the steak away from the direct heat to prevent it from scorching and turning black. Pull your steak once it reaches internal temperature for desired doneness.
Rest with butter. Transfer the steak to your cutting board, top with the pads of salted butter, and crack fresh black pepper across the top. Let the steaks rest for 10-15 minutes before slicing and eating.