1. Place chicken, veal shanks, and turkey drumstick in a large pot. Add enough water to cover meat by 4 inches (about 28 cups). Bring to a boil over high heat.

2. When broth comes to a boil, reduce heat to medium and set pot to one side so that it is partially off the burner. Fat and impurities will begin to rise and settle to the side of the pot that is off the burner. Cook broth, skimming off fat and impurities every 5 minutes, until broth looks clear, about 30 minutes. Add onions, celery, carrots, tomatoes, peppercorns and parsley. Continue cooking until broth is flavorful, about 2 hours more.

3. Strain broth and discard vegetables; reserve meat for another use. Use broth immediately or cool and store in an airtight container, refrigerated, for up to 1 week or frozen, up to 3 months.