How To Make Pickled Onions – Easy Pickled Red Onions Recipe – quick to make, with minimal prep work and just 5 basic ingredients. These pickled red onions are great for appetizers, antipasto platters, salads, soups, nachos, burgers, on top of pizza, sandwiches or tacos. These simple to make pickled onions add a great crunch to dishes, but also are great on their own, too!