Turkey burgers don't have the fat content beef burgers have and for safety reasons, they need to reach an internal temperature of 165º minimum when cooking and juices need to be clear. Grills cook with especially dry heat creating additional challenges. Cooking in a pot introduces oil. The pot not only sears the burger but steams the burgers with natural juices helping them retain moisture while cooking through. Cook one side until the burger defrosts and soften through. Flip over and to cook the other side and to reach the safe minimal internal temperature of 165º with a thermometer and juices are clear.