Take besan, ajwain, red chili powder, coriander powder, garam masala and salt in a bowl and mix well.
Add chopped onions, tomatoes and coriander to the above and mix well till the vegetables are coated with besan. You can add more vegetables to this, like carrots, spinach, methi etc to make it even healthier.
Mix in the yoghurt and little water at a time and make lump free batter.
Heat a non stick tawa on medium heat. Once hot drizzle about 1/2 tsp of oil. Once oil is hot, pour a ladle of batter and spread it to make a round shape like you would pour a dosa. Let the cheela gets cook on one side about 2 minutes or till gets golden brown. Flip and cook the other side as well
Repeat for all the batter. Serve hot with green chutney or ketchup.