Original Source: From the book Bird in the Oven by Mindy Fox
adapted by There's Always Thyme to Cook

1 roast chicken carcass, plus the neck, leftover meat saved separately
1 onion, with skin, quartered
2 shallots, with skin, cut in half
5 garlic cloves, with peel, smashed
3 carrots, washed and peeled, cut lengthwise in half
2 parsnips, washed and peeled, cut lengthwise in half
1 small turnip, washed, peeled and quartered
2 stalks celery, plus tops, washed and cut lengthwise in half
2 teaspoons whole black peppercorns
handful of fresh parsley, dill or any other fresh herbs you like
salt, to taste

Add all of the ingredients to a large stockpot and add cold water to cover by several inches. Over medium-high heat bring the water to just a boil, then lower heat to medium-low and simmer for 3-6 hours, uncovered for a very rich broth. Simmer for 2-3 hours for a lighter broth. Taste for seasoning, salt to taste.

Remove from heat, strain the soup into a container, discard the solids and cool the stock. Refrigerate and skim fat from the cooled stock. You can freeze the stock.