Trim and peel <quantity>4</quantity> red onions. Halve and thinly slice them

Place the onions inside a glass jar with a lid

Add <quantity>¼<unit>cup</unit></quantity> of white wine vinegar, <quantity>⅔<unit>cup</unit></quantity> of alcohol vinegar, and <quantity>1⅔<unit>cups</unit></quantity> of water to a saucepan over medium-low heat

Add <quantity>1<unit>cup</unit></quantity> of sugar

Add <quantity>2</quantity> dried bay leaves, <quantity>1<unit>tsp</unit></quantity> of black pepper, <quantity>1<unit>tbsp</unit></quantity> of mixed mustard seeds, and <quantity>1<unit>tsp</unit></quantity> of salt

Mix until the sugar is dissolved, and bring it to a boil

Cover the onions with the boiling brine. Close the jar and let it sit for at least 20m to pickle. The pickled onions are ready

Enjoy! Add them to a salad or a sandwich and you’ll be set!