Cut celery, onions and carrots. Place in roasting pan and sprinkle with olive oil, garlic powder, salt and pepper

Poke lemon with a knife, place whole lemon in cavity of chicken (can also use other herbs if desired)

Place chicken on vegetables in roasting plan. Pour olive oil all over chicken, sprinkle with salt and pepper

Place in 400°F oven, cook for about 90 minutes to 2 hours.