Use this classic stock in Southern chef Hugh Acheson's Baked Beans recipe.
Tie together leek, parsley, thyme, and bay leaves with a piece of kitchen twine; set herbs aside.
Place chicken carcass in a large stockpot along with onion, celery, tomatoes, tied herbs, and peppercorns. Add enough cold water to cover carcass by 2 inches.
Bring to a boil and immediately reduce to a simmer over low heat. Cook, skimming top as necessary, 2 hours. Strain and discard solids. Let stock come to room temperature before storing in covered containers.
Stock can be refrigerated up to 3 days or frozen for up to 2 months.