Save scraps of vegetables such as celery, onions, and carrots and place in a freezer safe gallon size bag as you cook your meals, place in freezer until bag is full or ready to use.
Remove meat from rotisserie chicken, use however desired. Reserve the carcass and any leftover meat still attached.
Place the chicken carcass in a large stock pot and cover with cold fresh filtered water.
Add vegetable scraps, garlic cloves, bay leaf, and whole peppercorns.
Cover with lid and bring the stock to a boil, once boiling turn heat down and simmer stock for at least 30 minutes or up to 3 hours.
Turn stove off, remove vegetables with slotted spoon. Test small sip of the stock, add desired amount of salt to taste.
Set large fine mesh pasta strainer over a larger bowl or stock pot and pour the remaining stock through, all vegetables and remaining carcass should be removed by these last 2 steps, leaving you with approx. 4 quarts of homemade chicken stock.
Cool at room temperature. Either store in refrigerator for 3-5 days or freeze for up to 3 months, or use immediately in a soup or stew that calls for chicken stock!