Ingredients:
- 1 large red onion, thinly sliced (about 8 oz / 225g)
- 1 cup (240ml) apple cider vinegar
- ½ cup (100g) granulated sugar
- 1/4 cup (60ml) water
- 1 tablespoon kosher salt
- 1 teaspoon black peppercorns
- 1 bay leaf
- 1/2 teaspoon red pepper flakes (optional)
Instructions:
- Thinly slice the red onion.
- In a saucepan, combine vinegar, sugar, water, salt, peppercorns, bay leaf, and red pepper flakes (if using).
- Bring the brine to a simmer over medium heat, stirring until the sugar and salt dissolve.
- Add the sliced onions to the simmering brine.
- Cook for 1-2 minutes, or until the onions begin to soften slightly and turn translucent.
- Remove from heat and let the mixture cool slightly.
- Carefully transfer the onions and brine to the sterilized jar. Ensure the onions are submerged in the liquid.
- Let cool completely, then seal and refrigerate for at least 30 minutes (ideally 1-2 hours) before serving.