Pickled red onions

There are a couple of different methods of pickling foods, hot and cold.  Both involve water and salt (a brine), and flavorings. 

I wanted pickled onions for my pork tacos.  I sliced a large red onion thinly and tossed it into a pot with 1/4 cup of cider vinegar, a tablespoon of sugar, a couple tablespoons of kosher salt, and enough water to cover.  I heated it up on the stove until all the sugar and salt disolved, then put the lid on until everything was cooled.

Pickling them got rid of a lot of the astringency, but left a nice onion-y flavor.