A cowboy steak is a thick (2 ½”-3”) bone-in ribeye cut between the ribs and feeds 1-2 easily.
 
For the perfect medium-rare thick-cut bone-in ribeye steak, grill for 18-20 minutes for a 2-inch steak, turning about 1 minute before the halfway point. A meat thermometer should read 130°F. Rest your steaks for 5 minutes before serving, covering lightly with foil.