Peel and thinly slice red onions with a knife or mandolin.
Into each mason jar, add 1 sliced onion, 1 tablespoon of black peppercorns and 6 cloves of garlic.
In a pot, bring water, white vinegar, sugar, salt and honey to a boil and turn off the heat. Stir to combine, and make sure the salt and sugar has dissolved.
Let the mixture cool down for a few minutes and then fill each mason jar with the pickling liquid. Secure the lid onto each jar and refrigerate.
Onions can be eaten after an hour but best after 24 hours. Store in regrigerater.
Notes
Vinegar - I used white vinegar, but you could also use apple cider, red wine, or even rice wine vinegar for an Asian style.