Prepare a charcoal or gas grill for medium heat (350° to 450°; you can hold your hand 5 in. above cooking grate only 5 to 7 seconds).
Sprinkle each steak generously with salt and pepper; rub with oil. Grill steaks, covered, turning once, until done the way you like, 10 to 12 minutes for medium-rare.
Transfer steaks to a large platter and top each with a slice of herb lemon butter.
Note: Nutritional analysis is per serving, without butter.