Dry brine the tomahawk 12 to 24 hours ahead of cook time. Pat the steak completely dry with paper towels, then season generously on all sides with kosher salt only at this stage. Place it uncovered on a wire rack set over a sheet pan and let it rest in the refrigerator overnight. This dry brine process draws moisture to the surface, which then reabsorbs into the meat along with the salt, seasoning the steak deep into the muscle and helping develop a better bark and crust later on. Do not skip this step on a cut this thick.

About 45 minutes before you are ready to cook, pull the tomahawk out of the refrigerator and let it come up toward room temperature on the counter. Mix together the black pepper, garlic powder, onion powder, smoked paprika, and cayenne in a small bowl. Apply this rub liberally to all sides of the steak, pressing it firmly into the surface so it adheres. The salt from the dry brine is already working in the meat, so this layer is purely about building that incredible bark and flavor crust.

Fire up the grill for a two-zone indirect setup. For charcoal, bank your lit coals to one side of the grill and leave the other side completely empty. Your target temperature for the indirect zone is a steady 225 to 250 degrees Fahrenheit. Add your wood chunk directly on top of the lit coals at this point. You want a thin blue smoke rolling out of the vents, not a thick white billowing smoke. Thick white smoke will make the steak taste bitter. Dial in your vents to hold that 225 to 250 degree range before you place the meat.

Place the tomahawk on the indirect side of the grill, bone side facing toward the heat source. Insert your thermometer probe into the thickest part of the eye of the steak, away from the bone. Close the lid and let it cook low and slow with minimal peeking. Every time you lift the lid you lose heat and smoke. Let the smoke do its work. You should start to see a beautiful smoke ring forming around the exterior of the meat within the first 30 minutes.

Monitor the internal temp closely as it climbs. This low-and-slow phase will take approximately 45 minutes to 75 minutes depending on the thickness of your steak and your grill temperature. You are pulling the tomahawk off the indirect heat when the internal temp reaches 115 to 120 degrees Fahrenheit for a target of medium-rare, or 125 degrees if you prefer medium. Once you hit that target temp, pull the steak off the grill and tent it loosely with foil while you prepare for the sear.

Now it is time to build your sear station. Open all the vents on your charcoal grill completely and add a full chimney of freshly lit charcoal on top of your existing coals. Let the grill rip up to 600 to 700 degrees Fahrenheit before you sear. If you are using a cast iron skillet, place it on the grill grates over the direct heat during this time so it gets screaming hot along with the grill. This high heat is what creates the Maillard reaction and builds that deep mahogany crust that makes a reverse seared tomahawk so extraordinary.

In a small saucepan or directly in a cast iron skillet on the grill, melt the butter with the smashed garlic cloves and rosemary sprigs. Let the butter brown slightly and the garlic become fragrant. This basting butter will be your secret weapon during the sear, adding richness, color, and incredible aroma to the crust. Keep it warm and close by your sear station.

Place the tomahawk directly over the hottest part of the fire. Sear for 60 to 90 seconds per side without moving it. Resist the urge to poke or press it down. Let the heat do the work. After flipping, spoon the garlic rosemary butter generously over the top of the steak while the bottom sears. Repeat on all sides including the edges by standing the steak on its side using your tongs to hold it in place. You are looking for a deep, dark, even mahogany crust across the entire surface of the meat. This searing phase should take no more than 4 to 6 minutes total.

Pull the tomahawk off the direct heat and check the final internal temp. For medium-rare you want to land at 130 to 135 degrees Fahrenheit. For medium, pull it at 140 degrees. Remember that the internal temp will continue to rise 3 to 5 degrees as the steak rests, so factor that carryover cooking into your pull temp. Do not cut into the steak yet no matter how tempted you are.

Rest the meat uncovered on a wire rack for a minimum of 10 minutes. Do not tent it with foil during the rest or you will steam the crust you worked so hard to build. The juices need this time to redistribute through the muscle fibers. After resting, slice against the grain, starting from the eye of the steak outward. Present it on a wooden cutting board with the full tomahawk bone intact for maximum visual impact. Finish with a pinch of flaky sea salt right before serving and watch your guests lose their minds.