Onion Uttapam is a classic and simple variation of Uttapam that is loved by many. It is made by adding finely chopped onions to the Uttapam batter. The onions add a sweet and crunchy texture to the Uttapam. You can also add some chopped green chilies and coriander leaves for extra flavor. Serve it with coconut chutney or sambar for a delightful breakfast or brunch option.