Place chicken bones, skin, or a whole chicken in a large pot
Add cold water to cover the chicken
Add onion, carrot, celery, garlic, bay leaves, and peppercorns
Bring to a boil over medium-high heat
Reduce heat to low and skim off any foam
Simmer gently for 1 to 3 hours
Add salt near the end if desired
Strain the broth through a fine sieve
Discard the solids
Let the broth cool
Refrigerate or freeze for later use