The trick to this dish is to flatten the chicken completely by removing the backbone which runs down the center of the bird. Turn the chicken over so the breast is lying flat against your cutting board. Using a sharp knife, while holding the chicken securely, you should cut lengthwise along both sides of the bone. As you see it emerge, pull out the bone while continuing to cut around it. It should come out completely. Then pull back on both wings to “break” the back and flatten the bird even more. Now it’s ready to get dunked in the marinade you’ve whisked together in a baking dish large enough to hold the chicken. Cover the dish and let the marinade work its magic for at least 30 minutes in the fridge. More is even better. Preheat your grill. Find a brick, large rock, or other heavy weight and wrap it in aluminum foil. Place the chicken on the heated grill, breast side up. Cover the grill if you have one. Cook for 15 to 20 minutes this way and then turn the whole chicken over so the breast side is flat against the hot grill. Place the weight on top of the chciken so the bird flattens out on the grill surface. Cover and cook another 30 minutes. Take off the weight and remove the chicken to a platter or plate. Cover tightly with foil and let stand 5 or 10 minutes so all the juices settle down. Cut the chicken in half or in quarters and serve with lemon wedges, roast fingerling potatoes and fennel, or another side dish. You'll be surprised how juicy and flavorful a whole chicken can be when grilled this way.