When it's not the day for a barbecue, it's time to use the hob. A cast iron griddle pan will give those lovely grill marks, plus you can get it very hot. Oil the burgers, not the pan, then cook on a reasonably high heat, turning once. Cooking times depend on the size of your burger but on average, allow three minutes per side for medium-rare, four minutes for medium and five minutes for well done.