Red onions are a type of onion with a mild to moderate, slightly sweet flavor and a crisp texture. They are a good source of vitamin C and fiber, as well as other beneficial plant compounds. Red onions can be eaten raw or cooked, and are commonly used in a variety of dishes such as salads, sandwiches, burgers, tacos, and stir-fries. They are easy to find in grocery stores year-round and are typically more expensive than other onion varieties. When selecting a red onion, look for one that is firm, heavy for its size, and has a shiny, deep-red or purple skin that is free from mold or soft spots. Store them in a cool, dry place away from sunlight for up to a few weeks. To prepare a red onion, cut off the root and stem ends, slice in half from top to bottom, remove the outer skin, and slice or chop as desired.