Preheat your oven to 325°F.
Rinse the chicken thoroughly and pat it dry with paper towels. Season the chicken with salt and pepper both inside and outside.
In a large roasting pan, heat 1 tablespoon of olive oil over medium heat. Add the onions, garlic, carrots, and celery, and cook until the vegetables are tender.
Pour in the chicken stock and stir to combine.
Place the seasoned chicken on top of the vegetables in the roasting pan.
Cover the roasting pan with aluminum foil, making sure to crimp the edges tightly.
Roast the chicken for 2-2.5 hours, or until the internal temperature of the chicken reaches 165°F. Baste the chicken with the juices in the roasting pan every 30 minutes.
Remove the foil and continue to roast the chicken for another 15-30 minutes, or until the skin is crispy and golden brown.
Remove the chicken from the roasting pan and let it rest for 10-15 minutes before carving.
Serve the chicken with the roasted vegetables and the pan juices.