These pickled onions are sharp, sweet and refreshingly acidic. We use a combination of fresh lime juice and apple cider vinegar. You can use just one acid, but we’ve found the combination adds a touch more complexity. There’s a lot of elbow room when it comes to adding spices or additional flavors. We use cinnamon sticks, cloves and red pepper flakes. Keep it clean and simple and add none or add a combination of the following: cinnamon sticks, whole cloves, crushed red pepper flakes, whole garlic, star anise, bay leaf, mustard seeds, fresh ginger slices, fennel seeds, coriander seeds or cumin seeds.
2 medium red onions, halved and thinly sliced
2 cinnamon sticks
6 whole cloves
Pinch crushed red pepper flakes
1 cup (240 ml) apple cider vinegar
1/2 cup (120 ml) freshly squeezed lime juice
1/4 to 1/2 cup (50 to 100 grams) sugar
1 tablespoon kosher salt
Add sliced onions to a medium bowl. Pour enough boiling water over onions so that they are covered. Count to 10 then drain. Add onions to glass jars (or glass container with lid).
Toast cinnamon, cloves and the red pepper flakes in a small saucepan over medium heat until fragrant, 3 to 5 minutes. Whisk in vinegar, lime juice, a 1/4 cup of the sugar and salt. Bring to a simmer and cook until sugar and salt have dissolved, 1 to 2 minutes. Taste for sweetness then add more sugar as needed. Pour brine over onions.
Allow to stand at room temperature until cooled, cover and refrigerate up to 2 weeks.