My friend had the decency to labor in her kitchen, make picked onions, and give me a jar. I've been using it every chance I get. yesterday I made some lentil-bulgar salad and added the pickled onions for a little sweet taste and I was very happy with the results. I recently made some red onion vinaigrette that also came out delish but totally ugly for a photo shoot. The red pickled onions are much prettier.
Here are a couple recipe for pickled onions.