Take the steaks out of the fridge 30 to 60 minutes before cooking.

With a paper towel, pat the steaks dry before adding salt and black pepper, as desired.

Oven temperature set to 300 °F.

For four to five minutes, heat a cast-iron skillet over high heat. Subtly incorporate the oil (it may splatter). The steaks should be seared for two minutes on each side. Get rid of the heat.

Depending on desired doneness (and the final temperature you're going for; see notes), bake the butter, garlic, and rosemary in the skillet for 3 to 6 minutes. When the internal temperature of the skillet hits 5°F below the desired final temperature, remove it from the oven.

The steaks should be basted with the butter sauce and rested for five to ten minutes before serving.