In a large stockpot, add chicken and fill with water until it is covered by a couple inches.
Add in the onion, garlic, salt, pepper, and any other veggies you are using.
Place the lid on and cook on low for 1 hour. I usually stir it half way through and flip it over.
Once it is cooked. remove it and set it on a plate to cool for about 20 minutes.
Once cool enough to handle, peel the skin off and throw it away, then pull all the chicken off the bones. I like to shred it, but it can also be removed and cut into pieces.