Optional: 1/2 tsp crushed red pepper flakes or sliced jalapeño for heat
Peel and cut the red onion in half. Thinly slice into half moons using either a knife or carefully using a mandoline.
In a small saucepan over medium/low heat, add the red wine vinegar, apple cider vinegar, water, maple syrup, kosher salt, all spice, and peppercorns. Stir and allow to heat through until the salt has dissolved, about 8-10 minutes.
In a sealable mason jar, add the sliced onions, sliced garlic, and optional red pepper flakes. Carefully pour in the pickling liquid (I transferred it to a measuring cup before pouring for safety and less mess). Seal the jar and give it a good shake. Place in the refrigerator and allow to chill/pickle for an hour before enjoying.
Prep time includes: prepping onions/garlic and the 1 hour pickling in the refrigerator.
Maple syrup is a sugar substitute, you can use regular sugar if desired
In a rush? You can microwave the water and dissolve the salt/sugar in there instead of using the stovetop method
Keywords: pickled red onions, pickling, red onion, pickled onion