If you are making this broth after making Whole Chicken in the Slow Cooker, after removing all of the edible meat from the chicken, add all the bones back with the cooking juices, onions and spices in the slow cooker.
Coarsely chop celery and carrot. Add bay leaf, celery and carrot to the slow cooker.
Fill the slow cooker almost to the top with water (leave about ½-1 inch at the top).
Cook on low for 10 hours.
Use a colander over a large soup pot to remove bones and vegetables and collect the broth in the large pot.
Use the broth for soup that week or freeze it for later use.