So after you’ve made the Rotisserie chicken in the crock pot…
Remove all chicken
Keep the onions and garlic in the crock pot
Put the bones back in the crock pot
Fill the crock pot almost to the top with water
Turn on Low for 8-10 hours (or overnight)
In the morning, ladle the stock through a fine sieve (r some cheese cloth) to remove all bones, etc
Refrigerate or freeze for future use!