In a large stock pot over medium high heat
Foam out butter
Add onions, carrots, and celery saute until onions are translucent
add garlic and continue to saute until fragrant (~1-2 minutes)
add chicken parts, or broken down rotisserie chicken
continue to saute and turn chicken for an additional 3-5 minutes
Add water, bay leaves, peppercorns, poultry seasoning, and return to a fast simmer
Reduce heat to medium low (slow simmer)
Cover and simmer for 2-3 hours, skimming scum occasionally, usually done by end of first hour
When the chicken begin to fall off the bones, remove from heat and cool
Use a slotted spoon or ladle to remove large pieces of chicken / vegetables
Filter stock through a large sieve / cheesecloth to remove any additional solids