Here’s my go-to red onion pickle recipe (from Suzanne Goin’s AOC cookbook.)

Place 1 peeled and thinly sliced red onion in a bowl or glass jar. In a non-aluminum pot, bring 1 cup water, ½ cup red-wine vinegar, ⅓ cup sugar, a small piece of cinnamon stick, 12 whole black peppercorns, 1 chile de árbol, 2 cloves, and 1 bay leaf to a boil. Pour the brine over the onions. Let cool completely and refrigerate. (To keep the onions crispier, set the bowl or jar in a bowl of ice water to help them cool faster.)

Canele’s pickled red onions:

I came up with this pickle as a garnish for the duck hash at Canele. In all honesty, I haven’t made it in 9 years, but Corina and I remember it being delicious. 

1 red onion, sliced into rings the thickness of your pinky finger (separate the rings so that each one gets pickled)

½ c sugar

¾ c red wine

⅓ c balsamic vinegar

⅔ c red wine vinegar

small piece of a cinnamon stick

1 Arbol chili

1 bay leaf

1 clove

6 black peppercorns

1 garlic clove

Put the sugar in a small saucepan and add a touch of water until it’s the consistency of wet sand. Turn on heat to medium and caramelize the sugar. When you have a light brown caramel, add the remaining ingredients and bring to a boil. Lower to a simmer and let the brine reduce, probably by a third. Put the onions in a bowl or jar and cover them with the brine. Chill.