01 - Preheat oven to 425°F.
02 - Combine minced garlic, lemon zest, lemon juice, olive oil, salt, pepper, thyme, and rosemary in a small bowl to create the marinade.
03 - Pat chicken dry with paper towels. Gently loosen skin over breast and rub half the marinade directly onto meat under skin. Rub remaining marinade over entire exterior surface.
04 - Stuff chicken cavity with lemon slices and additional thyme or rosemary sprigs if desired.
05 - Place onions, carrots, and celery in roasting pan. Position chicken on top of vegetables, breast side up.
06 - Roast for 1 hour 15 minutes until juices run clear when thigh is pierced and meat thermometer inserted into thickest part of thigh reads 165°F.
07 - Let chicken rest for 10 to 15 minutes before carving. Serve with roasted vegetables and pan juices.