Quick-Pickled Red Onions

Quick-pickled red onions are one of the most useful toppings you can keep in the fridge. A hot brine of vinegar, water, a little sugar and salt softens the onion's raw bite while keeping some crunch, and turns the slices a vivid pink. They are ready to eat in about 30 minutes and get better over the next day.

Their sharp acidity balances rich cheese and fatty beef, and they add color and snap to a smoky black bean burger. See more ideas in our best burger toppings guide.

1. Slice the onion. Peel the onion, cut it in half through the root, and slice into thin half-moons about ⅛ inch thick. A mandoline makes this quick; use the guard.
2. Pack the jar. Pack the onion slices into a clean 1-pint glass jar along with any add-ins.
3. Make the brine. In a small saucepan, combine the vinegar, water, sugar and salt. Bring to a simmer over medium heat, stirring until the sugar and salt dissolve, about 2 to 3 minutes.
4. Pour. Carefully pour the hot brine over the onions. Press them down with a spoon so they are fully submerged.
5. Cool. Let the jar sit uncovered at room temperature for about 30 minutes, until the onions turn pink and soften slightly.
6. Refrigerate. Cover and refrigerate. They are good to eat right away, and the flavor and color are best after a few hours or overnight.

• Slice thin and even. Uniform slices pickle at the same rate and drape nicely over a patty.
• Vinegar choice matters. Cider vinegar is fruity, white wine vinegar is clean, and plain white vinegar is the sharpest. Lime juice can replace part of the vinegar for a taco-style twist.
• Refrigerator pickles only. These are not processed for canning, so keep them in the fridge. They are best within about 2 weeks and will soften over time.
• Use a clean fork. Always use clean utensils to lift onions out of the jar.

Approximately 15 calories per serving. This is an estimate.