Pickled eggs have been around for centuries! Here's a recipe that embodies the bold, ancient traditions as to why these eggs were pickled for posterity.
In a large saucepan, combine the first eight ingredients. Bring to a boil. Reduce heat; cover and simmer for 10 minutes. Cool completely.
Put eggs and sliced onions in a large jar; add enough vinegar mixture to completely cover. Cover and refrigerate for at least 8 hours or overnight.
Use a clean spoon each time you remove eggs for serving. May be refrigerated for up to 1 week.