Preheat oven to 250f - the lower the better but the meat will take longer. Do not go over 275f.
Season Ribeyes on wire rack and baking tray setup. Lay foil under wire rack for an easier cleanup. Pat steaks dry then add about 1/2-1 tsp of salt and 1/8 tsp of pepper per steak. Salt generously! Remember the steaks are thick.
Place steaks in oven and cook for about 1 hour for 2 inch thick steaks. Time will vary based on size of steak. Start checking temperature of steaks with an instant read thermometer at 45 minute mark.
Remove steaks from oven at 115f for medium-rare. Medium-rare is 130f-135f. The steaks will be seared to this temperature so make sure to remove from oven at no higher than 115f-120f if medium-rare is desired.
Let steaks rest for 15 minutes before searing.
Preheat cast iron or heavy steel skillet on hottest burner to as hot as it will get. Give it a couple minutes to get super hot. Open a window and/or turn on exhaust vent because the searing process will create a lot of smoke.
Sear steaks for 1 minute on each side in 1-2 Tbsp of vegetable oil.
Add 2 Tbsp of butter during last 30 seconds of searing.
Remove steaks and pour butter mixture over top and serve immediately.
This recipe will work just as well with any thick steak. A porterhouse or NY strip would also make a perfect steak.