Grab that red onion and slice it thin—paper-thin if you can. Think “barely there” slices. You want these onions to soak up all the goodness, so don’t skimp on the slicing skills.

In a medium bowl, mix the apple cider vinegar, kosher salt, honey, and vanilla sugar. Stir it up until the salt and sugar are fully dissolved. If your arms aren’t tired, you’re doing great!

Add your thinly sliced onions to the bowl of liquid magic. Toss them gently until everything is coated. Then, press them down with the back of a spoon or your hands (no judgment) to ensure all the onions are submerged like they’re at a spa day. Cover the bowl with plastic wrap, pressing it right onto the surface of the onions to keep them snug in their vinegar bath.

Let the onions rest for an hour at room temperature. Yes, you’ll want to peek, but patience, my friend—this is where the flavor happens.

Transfer the onions and their brine to an airtight container, pop it in the fridge, and let them chill. They’ll keep for up to two weeks, but honestly, they’ll be gone long before that.