Onions have been preserved via Pickling since pre-history. Some of the first foods Humans ever pickled were more than likely Onions.
This particular recipe integrates cinnamon and mace into the Onion equation to create a delightful pickled onion.
2 pints cider vinegar
1/4 oz cinnamon sticks
1/4 oz whole cloves
1 dozen peppercorns
1/4 oz mace
1/4 oz whole allspice
2 bay leaves
Tie spices in a small piece of muslin, place in vinegar and allow to steep for about 1 to 2 months for a good flavor.
Place vinegar and spices in a glass or china bowl standing in a pan of water. Cover bowl, bring water to boil, remove from heat. Allow to get cool at least 2 hours.
Select small, even-sized onions. Place without peeling in a brine made from 1 lb salt to 1 gallon of water. You might want to place a plate on top to keep the onions submerged.
Leave 12 hours, peel and place in fresh brine for 24 hours.
Drain thoroughly, pack into screw-top jars, and cover with cold, spiced vinegar which should be half an inch above onions.
Cover securely with vinegar-resistant tops.
For best flavor keep about 3 months before eating.