Remove the tomahawk steak from the fridge and allow it to rest at room temperature for about 30 minutes.
Preheat your Z Grills pellet grill to high heat, about 450°F.
Pat the tomahawk steak dry using paper towels. Then, season it with salt and pepper.
Sear your tomahawk steak on high heat for 3-5 minutes on each side, turning a quarter of the way to develop a nice crust on the entire surface of the steak. This step will take between 6-10 minutes total, and each quarter will be done in 1 ½ to 2 ½ minutes.
Reduce heat to medium, about 350°F.
Cook the steak for 10-25 minutes, flipping once halfway through.
Remove the steak from the grill when the meat thermometer reads 140°F* when inserted into the center of the thickest part of the steak. Please note that 145°F is the recommended temperature to cook beef for safe consumption by the USDA. Tent the steak with aluminum foil. Allow the steak to rest for 5-10 minutes. During this time, the steak will continue cooking. The temperature will rise to 145°F, resulting in a medium steak.