Remove the tomahawk steak from the refrigerator 45 to 60 minutes before cooking
Pat the steak dry with paper towels
Season generously with salt and black pepper on all sides
Preheat the oven to 400°F
Place a cast iron skillet or oven-safe pan over high heat on the stovetop
Add a small amount of high-smoke-point oil to the pan
Sear the steak for 2 to 3 minutes per side, including the edges
Transfer the skillet to the oven
Roast until the internal temperature reaches your desired doneness
Remove at 120°F to 125°F for rare
Remove at 130°F to 135°F for medium-rare
Remove at 140°F to 145°F for medium
Remove at 150°F to 155°F for medium-well
Use a meat thermometer to check the thickest part of the steak
Remove the steak from the oven
Rest the steak on a cutting board for 10 to 15 minutes
Slice against the grain and serve