How to Make It
Preheat oven to 425°.
Cut the turkey carcass into quarters. Place the carcass, skin, carrots, celery, onion, and garlic on a jelly roll pan or shallow roasting pan. Bake at 425° for 45 minutes, stirring once.
Place turkey and vegetable mixture, water, broth, and peppercorns in a large stockpot. Bring to a boil; cover, reduce heat, and simmer 2 hours. Strain mixture through a sieve into a bowl, reserving stock. Discard solids. Cover and chill stock 8 hours or overnight. Skim solidified fat from surface; discard fat.
Note: Store the turkey stock in an airtight container in the refrigerator for up to a week, or freeze for up to 3 months.