Eastern North Carolina BBQ Sauce With Onions

Sauces

2 cups cider vinegar
1 tablespoon peppercorns
1 teaspoon celery seeds
1 teaspoon salt
1 tablespoon hot pepper flakes
1 onion; grated
1 cup water

Mix ingredients well and simmer for 15-20 minutes on low heat until onions are cooked through.