Gather chicken bones, carcass, or wings
Add chicken pieces to a large stockpot
Cover with cold water
Add onion, carrot, and celery if desired
Add salt, peppercorns, and bay leaf if desired
Bring to a gentle simmer
Skim off foam and impurities from the surface
Reduce heat to low
Simmer uncovered or partially covered for 2 to 4 hours
Add water if needed to keep ingredients covered
Strain the stock through a fine sieve
Discard solids
Cool the stock quickly
Refrigerate or freeze for storage