Indirect grilling means food is cooked by hot air circulating around the food, much like a convection oven. It is a slower cooking method because less heat is provided. You will want to refer to your owner's manual for specific directions. If you have a two-burner gas grill, after preheating with both burners, you will turn off one burner and place the food over the unlit side, away from the heat source. For three-burner gas grills, you will turn off the middle burner after preheating and place the food in the center of the grill. Drip pans are required for foods that have juices such as roasts and ribs. The food is placed on a rack in a roasting pan and the roasting pan is set on the grill rack. The lid of the gas grill is closed for grilling.