Remove the outer layer of the onion. With a sharp kitchen knife, or a mandolin set to very thin slices, slice the onion. Slice them as evenly as possible. Thinner slices allow for quicker pickling, thicker slices will stay crunchier.
Fill a large bowl with fresh cold water and add the onions to the bowl. Swirl them around and let them sit while you prepare the pickling juice. This step helps remove a lot of the strong raw onion flavor.
Measure out your water, apple cider vinegar, salt and honey into a saucepan. Over medium heat, warm up the pickling juice and stir until the honey and salt have dissolved.
Add the bay leaf. Once dissolved. Turn the heat off.
Drain the onions, and make sure that most of the water has dripped off.
Place the onions into your jar.
You can now pour the pickling juice over the onions. If you want softer onions, add the pickling juice while still hot. If you like your onions crunchier, let the juice cool down.
Hotter liquid will pickle the onions quicker and they could be ready in a few hours. Coldpickling juice will take longer and the onions will be ready the next day.
Make sure all the onions are covered with pickling juice and seal the jar. Once it has cooled down, place in the refrigerator.
OPTIONAL: If you are on Paleo or have reintroduced and can tolerate black bepper, then you can add some black pepper to the pickling juice. Crush them with the side of your knife, and add them at the same time you add the bay leaf.