1. To a large stock pot, add the carcass, celery, carrots, onion, garlic, bay leaves, salt (if using), peppercorns, thyme, and parsley. Fill the pot with cold water until the carcass is almost covered. Bring to a boil over high heat, then reduce the heat to low. Simmer, for 6 hours, checking on it and stirring occasionally. The liquid will reduce by about one third. Remove from the heat and let cool completely.

2. Remove and discard the carcass and any large turkey pieces and vegetables from the stock. Set a fine-mesh sieve over a large bowl. Strain the stock into the bowl.

3. Store refrigerated in an airtight container for up to a week or in the freezer for up to 3 months. To freeze, divide the stock between several, preferably 1-cup, containers.

To make in slow-cooker:

1. To the base of a slow cooker, add the carcass, celery, carrots, onion, garlic, bay leaves, salt (if using), peppercorns, thyme, and parsley. Add eater to the slow cooker until the carcass is almost covered, leaving at least 1 inch of space at the top. Cook on HIGH for 8-10 hours or LOW or 12-16 hours.

2. Remove and discard the carcass and any large turkey pieces and vegetables from the stock. Set a fine-mesh sieve over a large bowl. Strain the stock into the bowl.

3. Let cool completely. Store refrigerated in an airtight container for up to a week or in the freezer for up to 3 months. To freeze, divide the stock between several, preferably 1-cup, containers.

Make ahead version:

1. Instead of using a leftover turkey carcass, purchase 3 pounds of turkey wings and 1-2 turkey necks. The turkey necks are optional, but add so much flavor. You can ask for them at the meat counter at your local grocery store.

2. Preheat the oven to 450°F with a rack in the center position. Arrange turkey wings and neck (if using) on a large rimmed baking sheet. Roast in the oven, turning the turkey halfway through, until golden brown, about 45 minutes.

3. Transfer wings and necks to a large stock pot. Add the celery, carrots, onion, garlic, bay leaves, salt (if using), peppercorns, thyme, and parsley. Fill the pot with cold water until the wings and neck are almost covered. Bring to a boil over high heat, then reduce the heat to low. Simmer, for 6 hours, checking on it and stirring occasionally. The liquid will reduce by about one third. Remove from the heat and let cool completely.

4. Remove and discard the wings, neck and vegetables from the stock. Set a fine-mesh sieve over a large bowl. Strain the stock into the bowl.

5. Store refrigerated in an airtight container for up to a week or in the freezer for up to 3 months. To freeze, divide the stock between several, preferably 1-cup, containers.