Ingredients:

  • 1 medium red onion (approx. 8 oz / 225g), thinly sliced into half-moons
  • 1/2 cup (120ml) Balsamic vinegar
  • 1/2 cup (120ml) Warm water
  • 1 tbsp (15g) Granulated sugar
  • 1 tsp (6g) Sea salt
  • 1 clove garlic (approx. 3g), thinly sliced
  • 1/2 tsp (1g) Whole black peppercorns
  • 1/4 tsp (0.5g) Red pepper flakes

Instructions:

  1. Slice the red onion into very thin half-moons (roughly 1/8-inch). Pack the sliced onions and garlic cloves tightly into a 16 oz glass mason jar.
  2. Combine the balsamic vinegar, warm water, sugar, and salt in a small saucepan. Heat over medium heat for 3–5 minutes, stirring occasionally, until the sugar and salt have completely dissolved. Do not bring to a rolling boil.
  3. Let the brine cool for 2 minutes, then pour the hot brine over the onions in the jar, ensuring they are completely submerged.
  4. Add the peppercorns and red pepper flakes. Seal the jar and let it sit at room temperature for 30 to 60 minutes before refrigerating.