Rinse your chicken. Take items, if any, out of cavity and discard.
Poke your potatoes and put them in the bottom of your dutch oven in the middle so your chicken can sit upon them and not fall over.
Rinse vegetables, take top layer of onion off and cut in fourths.
Put 2 pcs of onion inside chicken cavity as well as a few pcs of veggies, enough to fill cavity. Leave carrots and celery in large chunks so they don't overcook.
Put remaining on the outside of your chicken inside the dutch oven. Rub olive oil on top, breast side, and season outside of chicken with seasonings of your choice (I use Lawry's, oregano, garlic powder, etc).
Put your lid on and put in the oven at 300 degrees for approximately 3 hours
Check after 2.5 hrs to see if chicken is at a safe 170 degrees using a meat thermometer and putting it inside the breast area.
You don't want to overcook it, and 3 hrs is perfect for our oven but each one differs slightly so just check.
Then remove your lid and cook with lid off for 15 minutes to brown the skin.