1Mix butter, feta cheese, olives, vinegar and 1 teaspoon seasoning in a medium-sized bowl with an electric mixer until blended. Chill until steaks are done.
2Sprinkle 3 tablespoons seasoning over the steaks, gently rubbing into the surface.
3Grill the steaks over direct high heat, with the lid closed as much as possible, until cooked to desired doneness, 15 to 20 minutes for medium-rare, turning once. Remove the steaks and top with the Balsamic Butter. Let steak rest 3 to 5 minutes before serving.