1#  red onions, 1/8" slice
3 cups cider vinegar
1-1/2 cups granulated sugar
1 bay leaf
2 arbol chiles, whole
1/2 tsp whole peppercorns
1/2 tsp whole allspice
1/2 tsp whole mustard seed
1 whole star anise (optional)
3 whole cloves
1 orange, halved

1.  Bring vinegar and sugar to a simmer, stirring until the sugar is dissolved.
2.  Add remaining ingredients except onions and simmer gently 20 minutes to incorporate flavors.
3.  Increase heat to high and bring to a rolling boil, then add the onions and stir gently to break up the onion rings.

5.  Remove from heat and pour through a strainer, reserve the liquid.
6.  Spread out onions on a rimmed baking sheet to cool.  At the same time, cool the pickling liquid.
7.  When the onions and liquid are cooled, combine them and store, tightly covered in the refrigerator.