If the meat's coming from the refrigerator, unwrap it and allow it to get up to room temperature, anywhere from 30-45 minutes. Salt it liberally (which means just to the point where you're beginning to feel uncomfortable about the amount); use a super salt such as Maldon or another salt where the crystals are both large and flat. Preheat the oven to 450 degrees. Coat a cast iron (preferred) or heavy-bottomed oven-safe skillet with a cooking fat that can tolerate torrid heat (avocado, safflower, soybean or ghee all do nicely). Put the skillet atop the burner and get it very hot.
Plop the steaks into the pan so that they don't touch each other and sear them for 2 minutes on each side (or 1 and 1/2 minutes a side if the steaks are less than 1 and 1/2 inch thick). Use tongs, not a fork. Then straight away, place the skillet into the oven.
Test the steaks with an instant-read thermometer after 3 minutes. The final cooking time will depend on the thickness of the steaks, their starting temperature, and the sturdiness of the skillet. It may take 5 minutes rather than merely three. You want to pull the steaks from the oven when the internal temperature registers 5 degrees below the following desired temperatures for doneness: rare, 120; medium-rare, 130; medium, 140; and - although you really oughtn't go here - 150 for medium well; and 160 for well done. (For example, if you desire a medium-rare steak on your plate, take it from the oven when the thermometer reads "125.") Immediately on removing the steaks from the oven, tong them from the skillet and place them on a cutting board to rest.
At this point, one listens to Anthony Bourdain: "It should rest on the board, meaning sit there at room temperature for 5 to 7 minutes, at which point, stay away from it. The steak continues to cook in these crucial moments and it must be left alone to ensure perfect distribution of the juices inside. All the difference in the world between a good steak and a totally messed up steak is going on in that period of time that you're just doing nothing. Don't wrap it in foil, don't cover it, don't poke it, don't prod it, don't even look at it. Just let it sit there. Leave it alone, and you will be rewarded."
~ Bill St John