These onions are wonderful piled on a burger, roll-up, or sandwich; tossed in a salad; or festooned over a plate of sliced tomatoes, drizzled with olive oil, and then finished off with a generous amount of freshly ground black pepper. They also make a colorful topping for just about any hors d'oeuvre. **These onions must stay refrigerated; even if you sealed the glass jar. They cannot be kept in the pantry!**
- Blanch 2 sliced red onions in a small saucepan of boiling water to cover for 1 minute and drain in a colander.
- Then return them to the pan and add a cup of cider vinegar, a teaspoon of salt, and just enough cold water to barely cover the onions.
- Bring to a boil over high heat and simmer the onions 1 minute.
- Transfer the onions and brine to a glass jar and chill.
- The onions will turn the color of a pink piñata and will get crisp as they cool.
- They'll keep for weeks in the refrigerator.