My second try on this technique. The first time they turned out ok, but not great - I cooked them low and slow (200°?) and still managed to overcook them in the oven. It was too bad, I'd bought some beautiful Ribeyes from Belcampo and they weren't as good as I hoped.

This time, though! The steaks were thicker, which might have helped, and I did higher heat in the oven (300°) but I think that helped me pay closer attention since I only needed to cook it for 15 minutes.

Great instructions for the process are at Serious Eats. The short version:

1. Prep like normal (salt maybe the day before, bring to room temperature)
2. Cook in the oven, ideally on a metal rack, until it's almost at your desired internal temperature (I'll copy the chart below)
3. Sear in a pan (ideally cast iron) with the burner as high as it will go. Add oil, then slide in butter just as you add the meat. It just takes 30 seconds or so a side, but you'll want to lift the meat during that time to get more oil underneath. Don't forget to sear the sides too, that'll make the fat crunchy and delicious.

Super easy! Well, pretty easy.

Chart for a 250°F oven (also from Serious Eats):