Quick-Pickled Onions

Ingredients (7)

• 1 medium red onion, very thinly sliced
• 1/2 cup water
• 1/4 cup distilled white vinegar
• 1/4 cup apple cider vinegar or additional white vinegar
• 1 1/2 tablespoons maple syrup or honey
• 1 1/2 teaspoons fine sea salt
• 1/4 teaspoon red pepper flakes (optional, for heat)