Grilling chicken whole keeps it tender and moist; if you butterfly it, the parts will cook evenly. Use kitchen or poultry shears to cut down either side of backbone; remove it. Spread chicken flat, skin-side up; tuck wings behind shoulders. Make a small slit in skin with knife at tip of breast near thigh; insert end of drumstick; repeat. If desired, rub with lemon and herbs. Grill chicken over medium heat, turning occasionally, until juices run clear when breast is poked with a fork, 30 to 45 minutes, depending on the size of the bird.