Place a stripped chicken or turkey carcass in a large stockpot with leftover or fresh vegetables such as carrots, onions, celery, and some herbs like parsley, a bay leaf and peppercorns. (Save all the tops and bottoms from chopped veggies for this purpose.) Cover with 3 quarts water and boil. Reduce to a simmer and cook, uncovered, for 3 to 4 hours. Skim off the foam occasionally. Strain through a colander into a bowl and cool.
Store in plastic containers or freezer bags; refrigerate if planning to use within 2 days, or freeze. Yields 2 quarts.