Preheat the grill to medium-high heat.
Add the chopped rosemary, olive oil, lemon juice, salt, and pepper to a large resealable plastic bag.
Using kitchen shears, cut down both sides of the chicken's backbone and remove the backbone.
Oil the grill grates, remove the chicken from the marinade and place the chickens skin-side down on the hot grill rack.
Place 2 foil-covered bricks on top of the chicken to weigh it down. Grill 20 minutes, then remove the bricks and flip. Continue cooking for 15 to 20 minutes longer, or until the internal temperature reaches 165 degrees F. Let the chicken rest for 5 minutes before carving.
Serve the chicken on a bed of arugula with lemon slices.
Wine suggestion for this recipe:
NotesYou can save the backbone and freeze for making stock. Lay the chicken out on a work surface and press down firmly with the heels of your hands to flatten. Add the chickens to the rosemary marinade, tossing to coat and place the chicken in the refrigerator for a minimum of 3 hours or overnight, for best results.