Pickled onions are small onions that have been preserved in a vinegar solution, often with added spices and sugar. This process enhances their flavor, making them tangy and slightly sweet. They are commonly used as a condiment or garnish in various dishes, adding a crunchy texture and vibrant color. These onions can be made from different varieties, such as red onions or white onions, and are popular in many cuisines around the world. They are often served alongside sandwiches, tacos, or as part of a charcuterie board, providing a flavorful contrast to richer foods.