Equipment: A clean quart jar with a tight fitting lid - canning jars or flip top gasket jars are the usual choices. I pour the pickling liquid into a Pyrex 2-quart measuring cup first, then into the jar - the spout makes it much less messy.

See my pickling vegetables basic technique for more details.

The pickles will keep in the refrigerator for up to 3 months. If you see fur or fuzz growing on top of the liquid, throw them out.

Pickled red onions are a traditional Mexican side dish, and they're great with tacos - especially beef tacos. Use them anywhere you'd use raw or grilled onions: on hot dogs, burgers and sandwiches, with grilled meats, or in potato salad.

Sweet onions: You can use some sweet (Vidalia) onions in place of the red onions. Red onions turn the pickling liquid a bright red, so a mix gives you a more muted color.

Wedges: Cut each onion into 8 wedges instead of thin slices. It looks better, but thin slices are easier to use.

Other spices: David Lebovitz uses allspice berries instead of coriander.

Lime juice: Add some lime juice to the pickling liquid - this is also traditional in Mexico.

Adapted from David Lebovitz's Pickled Red Onions.