1 large white onion cut into 1/8” thick rings

3/4 cup white vinegar

1/2 cup sugar

1/4 cup sherry vinegar

1/4 cup water

1 tablespoon kosher salt

1 teaspoon crushed red pepper flakes

1/2 teaspoon celery seed

1/4 teaspoon dried thyme

Put onion rings in bowl

Put all other ingredients is a pot or med/high heat.

Bring to a boil until the sugar and salt is dissolved about 5 mins.

Remove brine from heat and cool to room temp.

Pour cooled brine over the onions and let stand for 1 hour, toss them after about 30 mins. You can serve right after and they hold in the fridge for about 2 to 3 weeks.