For quick pickled red onions, thinly slice one small red onion and place in a small bowl. Pour distilled white vinegar in until it just barely covers them. Add salt and mix together. Press down on the onions to submerge them as much as possible. Let onions soak for as long as you like - they're great after 10 min. or after 40. After a little while, they turn a bright pink and will add a fun splash of color to your food. If you want to add a little heat, add some cayenne or crushed red pepper to the brine.