Wash and soak Dal in sufficient quantity of water for about 2 hours. Keep aside.
Roughly chop onion and green chili and keep aside.
Grind Dal with little water in the grinder. Don't make a smooth paste but grind it just coarsely.
Transfer grinded dal in a bowl and adjust the consistency with water, if needed. Batter should not be too thick and also not too thin at the same time. It must have a pourable consistency.
Now add chopped onion, green chilli, salt and red chilli powder and give a good mix to the batter. Do taste the seasoning by just taking a bit of batter on your forefinger. It is important because once all your chillas will be ready, you will not be able to adjust the taste.
Place non stick tawa on flame and apply little oil over it.
Now pour 2 to 3 scoopes of ladle on tawa and spread it evenly with the help of base of ladle. Let it cook on low to medium heat.
Pour few drops of oil around and over the chilla and flip over it once it is cooked from downwards.
Cook from both the sides. Once it turns golden brown from both the sides, it is done.
Your Green Moong Dal chilla is ready to be served. Serve hot with tomato ketchup or anardana chutney or any other dip/chutney of your choice.