Place the bones of the leftover roast chicken in a large pan or stockpot with any vegetables you have, such as onions, carrots and celery, and cover with cold water. Bring to a simmer and cook gently for 2-6 hours depending what time allows, but as a general rule the longer it can simmer, the better the flavour will be. Strain and either store for 3-4 days in the fridge or freeze and use from frozen when needed.
