We do this with rotisserie chickens. We pick off the meat we want for a few days and then I throw the whole bird into a stock pot FULL of water and let it simmer for hours until there's nothing but pile of loose bones left at the bottom of the pot. I run it through a strainer and I can fill at least a 32 oz. Mason jar with the chicken gravy and keep it in the fridge. I pour a little over our dogs kibble and he devours it.