In a bowl mix together aquafaba, besan, salt and egg replacing powder.
Add enough water to make a thin batter.
in a tawa, heat oil and add the onions and green chillies.
Sauté until translucent.
Now arrange them into a round on the tawa.
Pour the besan mixture on the onions, covering the entire round.
Cook until the omelette firmu up.
Gently transfer it to a plate.
Now use that plate to flip the omelette back on the tawa.
Cook until done on medium flame.
Serve it hot garnished with coriander leaves.