If the tomahawk is refrigerated, remove it and let sit on a wire rack set over a sheet tray for 45–60 minutes so it approaches room temperature (not longer than 90 minutes). Pat the entire surface and the exposed bone dry with paper towels.

Dry-brine

Evenly coat both sides and the exposed meat portion of the bone with kosher salt (about 2 tbsp total). If you prefer a lighter salt, use 1–1½ tbsp. Place back on the rack and refrigerate uncovered for at least 1 hour or up to overnight. If refrigerating overnight, let sit out 45–60 minutes before cooking to take the chill off.

Season

Just before cooking, mix the cracked black pepper, garlic powder, and smoked paprika (if using). Pat the salt to redistribute if dry-brined long, then press the pepper mixture evenly onto both large faces and the edges of the steak so it forms a coarse crust.

Cooking (Reverse-Sear Method — recommended)

Preheat oven

Preheat your oven to 250°F (120°C). Position a rack in a shallow roasting pan or on a wire rack set in a rimmed sheet pan.

Slow roast to temperature

Place the seasoned tomahawk on the rack. Insert an instant-read probe thermometer into the thickest part of the meat, avoiding the bone. Roast in the oven until the internal temperature reaches 115°F (46°C) for rare, 125°F (52°C) for medium-rare, or 135°F (57°C) for medium. For a 2–2.5 lb tomahawk this typically takes 30–50 minutes depending on oven and starting temperature. Remove from the oven and tent loosely with foil while you prepare the sear.

Heat the pan

Place a large heavy skillet (cast iron preferred) over high heat. Add the neutral oil and heat until shimmering and just beginning to smoke.

Sear the steak

Carefully transfer the tomahawk to the hot skillet. Sear each large face for 60–90 seconds until a deep brown crust forms. Sear the edges (including the fat cap and around the bone) by holding the bone with tongs or using a tong-and-spoon technique, rotating to render and brown all sides (about 1–2 minutes total on edges).

Baste with butter

Reduce heat to medium. Add the butter, smashed garlic cloves, thyme, and rosemary to the pan. As the butter foams, tilt the pan and use a spoon to continuously baste the top of the steak with the melted butter and aromatics for 60–90 seconds, building flavor and crust color.

Resting & Optional Pan Sauce

Rest

Transfer the tomahawk to a cutting board and spoon some of the buttery pan juices over the top. Tent loosely with foil and rest for 10–15 minutes. Internal temperature will rise ~5–8°F (3–4°C) during resting.

Optional pan sauce

While the steak rests, pour off excess fat from the skillet, leaving about 1–2 tbsp and any browned bits. Place skillet over medium heat, add the red wine/sherry and scrape up browned bits, reduce by half, then add the stock and simmer until slightly reduced to a saucy consistency (3–5 minutes). Swirl in 1 tbsp cold butter off heat for gloss, season to taste with salt and pepper, and strain if desired.

Slice & serve

Carve the tomahawk by slicing the meat off the bone and cutting across the grain into 1/2-inch (1.3 cm) slices, or slice whole crosswise while on the bone for presentation. Spoon any resting juices or the pan sauce over slices and garnish with the reserved thyme sprigs if desired.