Prepare the grill. Preheat oven to 400° F.
Let the steaks sit at room temperature for about 20 minutes while you wait for the coals.
Season the potatoes with salt, pepper and olive oil and bake in a 350-degree oven until tender, approximately 20 minutes. Remove and re-season with salt, pepper, rosemary and garlic. Bake for an additional 5 minutes.
Grill the steaks over hot coals, about 4-5 minute per side for 22-ounce, 1 ½-inch thick steaks to medium-rare. Adjust time for the size of steak and desired doneness. Cover steaks with foil and let them rest. Serve with potatoes alongside.