01 - Preheat oven to 400°F (200°C).
02 - Arrange onion slices and carrot chunks in the bottom of a large roasting pan to create a flavorful vegetable bed for the chicken.
03 - Rub the entire chicken surface with olive oil, then evenly coat with kosher salt, black pepper, and fresh lemon zest.
04 - Fill the chicken cavity with halved lemons, halved garlic bulb, and fresh thyme sprigs to infuse flavor from within.
05 - Secure the legs together with kitchen twine and tuck the wings snugly under the body for even cooking.
06 - Place the chicken breast-side up directly on top of the vegetable bed in the roasting pan.
07 - Roast for 1 hour 10 minutes, basting once or twice with pan juices, until juices run clear and internal temperature reaches 165°F (75°C) when tested in the thickest part of the thigh.
08 - Allow the chicken to rest for 10 minutes before carving to redistribute juices. Serve with pan juices and roasted vegetables.