Pat dry steak with paper towels and generously sprinkle with salt and pepper all over
Leave out on counter for 30-45 minutes until steak is at room temperature
Preheat your oven to 350°F (180°C)
Heat bbq to around 450°F (230°C). Make sure the grill grates are clean and well-oiled to prevent sticking
Place Tomahawk Steak on the pre-heated grill grates and sear it for 3-4 minutes on each side, including the fat cap
Remove steak and place onto an oven safe cooling rack, over a baking sheet to catch juices. Insert temperature probes in the thickest part of the Tomahawk
Place in pre-heated oven and continue cooking until the desired internal temperature is reached, following the bbq temperature guide
Heat butter, garlic and fresh rosemary over medium heat until melted and infused
Remove steak from cooling rack. Pour butter infusion over the steak and cover with foil. Rest for 10-15 minutes
Slice the steak against the grain into thick, visually appealing portions for serving. Serve with your favorite vegetables