How to Make It
Light a grill or preheat a grill pan. Brush the steaks and onion wedges with oil and season with salt and pepper. Using tongs, rub 1 of the onion wedges all over the grate or grill pan. Add the steaks and remaining onion wedges to the grill, cover and cook over moderately high heat, turning once, until the steaks are just medium-rare and the onion is tender, 6 to 7 minutes total. Transfer the steaks and onion to a cutting board and let rest for at least 10 minutes.
Return the steaks to the grill and cook, turning once, until the surfaces are just hot, about 2 minutes total. Transfer the strip steaks to the cutting board, slice them across the grain and serve with the grilled onions.