Toast the pine nuts in a small dry sauté pan on the stovetop over medium-low heat just until they begin to show color, 2 to 3 minutes.  Immediately transfer them to a plate to cool.

In a food processor, blend the olives, parsley, rosemary, garlic, lemon zest, olive oil, optional salt, and pepper.  Add the cooled pine nuts and process until smooth.  This can be made ahead and stored tightly covered in the fridge for up to 1 week.

NOTE:  Kalamata olives tend to be naturally salty.  It is advisable to taste the tapenade before adding additional salt.

In a small bowl, combine the olive oil, lemon zest, lemon juice, garlic, rosemary, salt, and pepper.  Stir well and set aside while you prepare the chicken.

Place the chicken on a cutting board or a flat surface covered with protective paper.  Using a boning knife or kitchen shears, cut along either side of the backbone or breastbone.  With your fingers, lift the bone away from the bird and set it aside. Flip the chicken over so the skin side is up and flatten with the heel of your hand. 

Taking care not to tear the skin of the bird, lift the skin by gently running your hand between the skin and the meat.  Place 1 tablespoon of tapenade under the skin of each leg.  Place about 4 teaspoons of tapenade under the skin of each breast.  Gently massage the tapenade under the skin to distribute evenly.

Place the chicken in a ceramic or glass dish just large enough to hold it flat.  Pour the marinade over the chicken, turning the bird to coat with marinade.  Cover the dish with plastic wrap and refrigerate for at least 4 hours or overnight.  Turn the chicken 3 or 4 times while marinating.

Remove chicken from refrigerator at least 20 minutes prior to grilling.  Turn a gas grill to high or ignite charcoal.  When the grill is hot, clean your grill rack.  Decrease the temperature to medium and wipe a bit of olive oil over the grill rack. 

Sprinkle the outside of the chicken with about 1 teaspoon salt on each side, and place it, skin-side up, on the grill. Set a cast-iron skillet on top of the bird, and place a foil-wrapped brick in the skillet.  Cook for 10 to 13 minutes, then remove the skillet and the brick, turn the bird, put the skillet and brick back in place, and cook for another 10 to 13 minutes.

Add the cut lemons to the grill, cut-side down, during the last few minutes of cooking.

The bird is done when it is golden brown and crisp on the outside and an instant-read thermometer registers 170°F when inserted in a thigh but not touching a bone.  Transfer the chicken to a cutting board or platter, cover with foil, and allow it to rest for 5 minutes.  Cut in quarters and season to taste with additional salt & pepper.  Serve with the grilled lemon halves for squeezing over the bird.