Garlic is a phytonutrient--a plant nutrient. It's not necessary for life, but it may have some healthful benefits and lots of flavor!
When grilling over indirect heat, food is cooked away from the heat. If using coals, arrange them around the edge of the firebox, and place a drip pan under the grilling area. If using a dual-burner gas grill, heat only one side, and place the food under the burner that is not lit. For single-burner gas grills, place food in a foil tray or on several layers of aluminum foil and use low heat.