About 3-4 hours before cooking, lather your tomahawk steaks with oil. In a bowl, mix the garlic salt & black pepper. Thoroughly season the steaks and place in the fridge to set until you are ready to grill.
While steaks are resting in the fridge, mix the steakhouse butter ingredients together. Roll into a log using parchment paper or plastic wrap. Place in the fridge until ready to use.
Using Cowboy Charcoal, fill two chimneys full of coals, light and let preheat for your grill for medium-high heat (350F).
Once the coals are white hot, blow off any loose ash and lay the tomahawk steaks down. Sear both sides for only 1-2 minutes until they are starting to brown.
Once they are seared, pull the steaks off and spritz the coals with a little water to lower the temperature to a medium heat (about 325F). Lay the steaks back down.
Cook over this lower heat, flipping & moving around on the coals every 5 minutes, for about 20 minutes until the internal temperature reads 120F for medium rare. Add a little additional seasoning to any bare spots on the steak.
Once the steaks are done, slice the butter into sections. Pull the steaks off, top with 1-2 butter sections per steak and rest for 10-12 minutes.
For serving, slice into them and enjoy!