Firstly, put the chicken carcass and any extra bones in a pot and cover with water. Then add celery, carrots, onions, bay leaf, parsley, salt and pepper. Bring this to a boil, lower and ladle off any foam that has risen to the surface. Simmer, uncovered, for about 45 minutes or so. I truthfully go about my business and when the vegetables are done I remove the bones and carcass and strain the stock through a sieve. The stock is then set to cool to room temperature and placed in the refrigerator overnight. I strain the stock once more then I either use it in a yummy soup or risotto dish right then or put it into containers to freeze.
A bouquet garni made with some fresh herbs is also a nice addition. This one was strung together with parsley, sage, and thyme.