Put the whole chicken with giblets into a large soup pot and cover it with water.
Add 1 whole unpeeled onion. 2-3, 4-inch celery stalks and leaves, 1-2 large unpeeled carrots. several sprigs of parsley. and 2 bay leaves.
Bring the pot to a boil and simmer on low for 3 hours or more.
Let the broth sit until cooled.
(optional) Refrigerate overnight to let flavors congeal.
Remove the chicken and other large pieces of vegetables and place them into a large bowl.
Remove the meat from the chicken and place it into another large bowl.
Discard the chicken skin, bones, and vegetables.
Strain the broth using a sieve into a bowl or large pot.
Let it sit for a while until fat rises to the top.
Skim off the fat using a large soup spoon or a fat skimming pitcher.
Place the skimmed and defatted broth into a soup pot.