This homemade pickled red onion recipe is the best way to brighten up any dish. Try a spoonful over salads, or add them to your grilled burger or sandwich for an instant flavor boost.
Combine vinegar, water, sugar, and salt; bring to a boil. Remove from the heat add the mustard seeds and black pepper.
Blanch the onions in boiling, salted water for 15 seconds. Drain well and combine with the vinegar mixture.
Cool to room temperature, cover and refrigerate until needed.
Serve with burgers, panini, and salad.