By leaving chickens whole, you avoid having to do all that flipping, one leg at a time, and maintain the juices. Crushed-olive tapenade, tucked under the skin, jams flavor right into the flesh while lemon-garlic marinade adds even more flavor on the exterior. Flattening the birds under a cast-iron skillet (weighed down by a brick) means they cook more evenly and retain flavor.
For the Kalamata tapenade
• 4 tbsp pine nuts
• 4 cups pitted Kalamata olives
• 4 tsp chopped fresh flat-leaf parsley
• 1/2 tsp minced fresh rosemary
• 2 garlic cloves, chopped
• 1/2 tsp grated lemon zest
• 2 tsp extra-virgin olive oil
• 1/2 teaspoon coarse sea salt, preferably gray sea salt
• 1/4 tsp freshly ground black pepper
For the lemon-garlic marinade
• 1/2 cup extra-virgin olive oil
• 4 tbsp grated lemon zest
• 2/3 cup fresh lemon juice
• 4 tbsp minced garlic (12 cloves)
• 2 tbsp minced fresh rosemary
• 2 tsp kosher salt
• 2 tsp freshly ground black pepper
For the tapenade, toast pine nuts in a small skillet over medium burner, tossing occasionally for 2 to 3 minutes until lightly colored. Put in a food processor with olives, parsley, rosemary, garlic, lemon zest, olive oil, salt, and pepper. Blend until smooth.
For the marinade, combine all ingredients in a bowl and stir.
Use scissors to remove chicken's backbone, then cut down the center of the breast, separating the chicken into halves.
Taking care not to tear the skin, use your fingers to loosen a flap at the cut edge of each thigh and also at the base of each breast. Push one tablespoon of tapenade under the skin of each. Massage skin to spread.
Place chicken halves in a pan large enough to lay flat. Pour on the marinade and refrigerate for 4 hours, turning every half-hour. Two hours before cooking, take out of the fridge to reach room temperature.
When grill is hot, sprinkle chicken with salt and place it, skin-side up, off to one side of the grill (not directly over the hottest embers or flame). Set skillet on top of the chicken halves, followed by a foil-wrapped brick. Cook for 10 to 13 minutes, turn over, put skillet and brick back in place, and cook for another 11 to 13 minutes. Add cut lemons to the grill, cut-side down, during the last few minutes of cooking. The bird is done when golden brown and crisp on the outside (or when instant-read thermometer reads 170 degrees at center of a thigh – but not touching bone).
Take chicken off grill, transfer to a cutting board, tent with foil, let rest for 5 minutes. Cut legs into thigh and drumstick pieces. Cut breasts in half. Sprinkle with salt, serve on a platter with the grilled lemon halves.