For moong dal chilla, soak the moong dal overnight or for at least 2 hours. Strain the soaked moong dal, then add cumin, turmeric, heeng, salt, curry leaves, green chilli, ginger, and roughly diced onions. Now, we just have to grind all of these. Add a dash of water while grinding to make it a smooth paste. The batter is ready; you can adjust the consistency by adding water.