1. Puree basil, pine nuts, Parmesan cheese olive oil, rosemary leaves, garlic, salt and pepper in blender until almost smooth. Set aside.
2. Place lemons in cavity. Fasten neck skin over back with toothpicks. Tie legs to tail. Spread half the pesto under the skin. Rub remaining pesto over chicken.
3. Heat oven to 375 degree F. Place chicken, breast side up, on a rack in a shallow roasting pan. Roast, uncovered, 1 hour 25 minutes to 2 hours, or until an instant-read thermometer inserted in thigh registers 180 degree F.
4. Transfer chicken to a cutting board. Cover loosely with foil; let stand 10 minutes. Makes 4 servings.