Add gram flour to a mixing bowl and make smooth batter by adding 1 cup water little at a time. Ensure that no lumps are formed in the batter. If required add more water. Ensure that the batter is not too thick.
Add all other ingredients namely chopped onion, chopped tomatoes, chopped coriander leaves, green chilies, turmeric powder and cooking soda and salt to taste and mix well.
Heat a tava/ frying pan.
Grease it with 1 teaspoon oil after it gets heated.
Reduce the heat and pour a ladle full of batter on the tava/frying pan.
Cover the frying pan with lid for 5 minutes.
After 5 minutes, spread ½ teaspoon oil on the eggless omelette and flip to the other side. Fry for further 5 minutes.
Serve with tomato sauce or green chutney.