Quick Pickled Red Onions

from ButterYum

makes 2 cups

Ingredients

1 medium red onion (about 5 ounces), halved and thinly sliced (1/8-inch slices)
1/2 cup water
1/2 cup distilled white vinegar
2 1/2 teaspoons sugar
1 teaspoon fine sea salt
1 teaspoon freshly minced garlic
1/2 teaspoon mustard seeds (see notes below)

Place onions in a glass jar that has a tight-fitting lid.
In a non-reactive container (glass, plastic, stainless, ceramic), make the pickle solution by combining together the water, vinegar, salt, sugar, minced garlic, and mustard seed; stirring until salt and sugar are completely dissolved.
Pour pickle solution over the onions; rest for a few hours or overnight before using.
Cover jar with lid and chill leftovers; they will last in the fridge for several weeks.

For the best flavor, Pete prefers to use brown mustard seeds - If you can’t find them, yellow mustard seeds may be substituted.
Avoid mixing the pickle solution in “reactive'“ containers such as unlined cast iron, unlined copper, or aluminum. Examples of non-reactive containers are enameled cast iron, tin-lined copper, stainless steel, glass, or ceramic, plastic.
Pickled onions are great on more than just burgers - use them on pull pork, potato salad, tacos, beans, tossed salads, etc.