I use an oven probe and cook in the oven with probe at 275 degrees until the steak is 95 to 105 degrees inside (less = more rare). A little salt is on top while it bakes. Then I finish off in a frying pan searing the top and bottom for 2 minutes (using olive oil or beef tallow), then 1:30 minutes and around the edges so the fat looks pretty. Then let the steak rest under a foil tent for 10 minutes. This last step is very important.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
I can squat 180lbs, press 72.5lbs and deadlift 185lbs