Salt the tomahawk generously and let it sit at room temperature for 45 minutes to an hour before it goes anywhere near heat. A steak this thick needs the head start, or the center will still be cold when the outside is done.

Reverse-sear it: oven at 250F with a thermometer in the thickest part, until it reads 115 to 120F internal. Pull it there, not later, since the crust at the end will carry it the rest of the way.

Finish in a screaming-hot cast iron, basting with butter, thyme, and garlic as it sears, about 60 to 90 seconds a side for the crust. Rest 10 to 15 minutes before slicing it off the bone.

This method gives you edge-to-edge even doneness instead of a thick gray band around a small pink center, which is the usual problem with searing a cut this thick straight from the fridge.