Preparation / Directions:
1. Splitting the chicken for grilling: Using a large Knife or Kitchen shears, cut down both sides of backbone of 1 chicken, through the joints where the legs attach, then on through the ribs; remove the backbone. Open the chicken out flat on your cutting board, skin-side up, press on the breastbone to loosen it so the chicken will lie flat. For the nicest presentation, make a small incision through the skin toward the bottom of each thigh and press end of the nearest drumstick through it; this will hold the leg in place as the chicken is grilled. Repeat with the second chicken, then lay them in a non-corrosive bowl.
2. Marinating the chickens. Puree the last 7 ingredients in a blender or food processor. Pour the mixture over the chickens and rub them to coat thoroughly. Cover and refrigerate at least 4 hours (or, preferably, overnight), turning the chickens several times.
3. Grilling and serving the chickens. About 1-1/4 hours before serving, light your charcoal fire, let it burn until coals are only medium-hot, then position the grill about 8 inches above the coals and lightly oil it. Lay the chickens on the grill, skin side up, and grill for 35 to 45 minutes, turning every 10 minutes and basting with any leftover marinade. They are ready when tender, and when a fork pricked deep into the thigh brings up clear (not pink) juices. (During the final 10 minutes of cooking, grill the onions, as described on page 277-charcoal-Grilled Baby Onions if you are using them.) Cut the chickens into quarters, lay them on a warm platter and serve.
Timing and Advance Preparation: Spend 1/2 hour preparing the chicken and marinade at least 4 hours ahead; it will take 1-1/4 hours to finish the dish, a good part of it spent waiting on the fire and the chicken. The chicken may marinate for a couple of days, but its texture will be best when grilled just before serving.
Traditional Variations Grilled Chicken with Another Flavor: Prepare the recipe as directed, using the following marinade: pulverize 1/4 teaspoons coriander seeds, 1/4 teaspoons black peppercorns, 1/2-inch cinnamon stick, 1/8 teaspoon whole cloves and 1 bay leaf, then mix with 1 teaspoon salt, 1 teaspoon mixed herbs, 2 teaspoons paprika, 1/2 cup vinegar and 4 roasted cloves of garlic (peeled and mashed to a paste).