Onion Uttapam is a popular variation of the traditional Uttapam. It is made by adding finely chopped onions to the batter, which gives it a sweet and tangy flavor. The onions become caramelized when cooked, adding a delicious crunch to the dish. Onion Uttapam is usually served with coconut chutney and tomato chutney, making it a perfect breakfast or brunch option.