Ingredients:

  • 2 medium red onions (about 450 g), peeled and thinly sliced
  • 1 cup (240 ml) apple cider vinegar
  • 1/2 cup (120 ml) water
  • 1/4 cup (85 g) honey
  • 1 teaspoon (6 g) fine sea salt
  • 1 teaspoon (2 g) red pepper flakes

Instructions:

  1. Peel the onions and trim off the root and stem ends.
  2. Cut each onion in half from root to stem. Lay each half flat and slice it into strips about 1/8 inch (3 mm) thick.
  3. Separate the slices into rings. They should fall apart easily, not stay in clumps.
  4. Pack the onion slices loosely into a clean 1-quart glass jar or two pint jars. Press them down gently so they fit without being crushed.
  5. Combine the vinegar, water, honey, salt, and red pepper flakes in a small saucepan.
  6. Set the pan over medium heat. Stir occasionally for about 2 to 3 minutes, until the liquid steams, tiny bubbles form at the edges, and the honey dissolves completely.
  7. Keep the brine at a gentle simmer, not a hard, rolling boil.
  8. Remove the pan from the heat once no honey streaks remain and the liquid looks clear.
  9. Slowly pour the hot brine over the onions until they are fully submerged. If any slices poke above the surface, press them down with a fork.
  10. Let the jar cool on the counter for about 15 to 20 minutes, until it is warm to the touch.
  11. Cover the jar with its lid and refrigerate for at least 30 minutes. For the best flavor, chill for 2 hours or overnight.
  12. Before serving, check that the onions look translucent, have turned a rosy pink, and are softer but still crisp.