01 - Set the oven to 400°F and allow it to reach temperature before roasting.
02 - Pat the chicken dry with paper towels. Rub olive oil, salt, pepper, and paprika evenly over the skin.
03 - Insert half the lemon, several thyme sprigs, and two smashed garlic cloves into the chicken cavity.
04 - Place onions, carrots, celery, remaining garlic cloves, and thyme in a large roasting pan. Squeeze juice from the other half of the lemon over the vegetables, then add the squeezed lemon halves to the pan.
05 - Place the chicken breast-side up atop the vegetable bed in the roasting pan.
06 - Roast for 1 hour and 15 minutes, basting with melted butter at 30 and 60 minutes. Roast until skin is golden and internal temperature at the thickest thigh part reaches 165°F.
07 - Let the chicken rest loosely covered with foil for 10 minutes before carving. Serve with the roasted vegetables and pan juices.