easy picked onions

I love picked onions.  Makes my mouth water just thinking about them.  I needed some pickled onions for some tacos I was making and found this simple recipe which is better than the recipe I had been using.  So quick and easy!!

easy pickled onions (shared appetite)
1 medium red onion, thinly sliced
1/2 cup apple cider vinegar
1 cup warm water
1 tablespoon sugar (I used 1 1/2 teaspoons)
1 1/2 teaspoons kosher salt

Combine vinegar, water, sugar and salt in a medium bowl or large liquid measuring cup.  Whisk together until sugar and salt is fully dissolved.
Place onion in a jar or bowl (I used a mason jar).  Pour vinegar mixture over and let sit at room temperature for at least 1 hour if you're in a rush.  Preferably, cover and refrigerate for at least a day.  Pickled onions will last a few weeks stored in the refrigerator.