Three-lemon chicken

1 head of garlic
1 teaspoon extra-virgin olive oil
For the paste:
Lemon zest from 2 lemons
2 tablespoons fresh lemon juice, divided
1-1/2 teaspoons finely chopped fresh rosemary
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
1 whole chicken, 4 to 5 pounds
Kosher salt
Freshly ground black pepper
4 sprigs fresh rosemary
1/4 cup dry white wine
1 whole lemon, thinly sliced (optional)

1. Remove the loose, papery outer skin from the head of garlic. Cut about 1/2-inch off the top to expose the cloves. Place on a large square of aluminum foil. Drizzle the olive oil over the cloves. Fold up the foil sides and seal to make a packet, leaving a little room for the expansion of steam. Grill over Indirect Medium heat until the cloves are soft, 30 to 45 minutes. Remove the garlic from the grill and allow to cool. Squeeze the garlic from the individual cloves into a small bowl.
2. To make the paste: In the bowl with the garlic, combine the lemon zest, 1 tablespoon of the lemon juice, rosemary, salt and pepper. Mix well.
3. Remove and discard the neck, giblets, and any excess fat from the chicken. Rinse the chicken, inside and out, under cold water and pat dry with paper towels. Loosen the chicken skin gently with your fingers and spread half of the paste under the skin on the breast. Season the inside of the chicken cavity with salt and pepper and add the rosemary sprigs. Truss the chicken with cotton string. Pour the remaining 1 tablespoon of lemon juice and the wine into the cavity. Coat the outside surface of the chicken with the other half of the paste, pressing it into the skin.
4. Grill the chicken, breast side up, over Indirect Medium heat until the juices run clear and the internal temperature reaches 170 F in the breast and 180 F in the thickest part of the thigh, 1-1/4 to 1-1/2 hours. Halfway through grilling, slide three lemon slices under the string on top of the breasts.
5. Transfer the chicken to a platter, loosely cover with aluminum foil, and allow to rest for about 10 minutes before removing the string and carving. Serve warm.