Take all the ingredients(except oil & onions) in a bowl
Add water
The batter should be very thin-just watery

Keep aside for ten minutes
This resting time will let rawa swell up

Heat a non stick pan
Spread chopped onions
Now pour the batter with your hand like you sprinkle (see video link shared in the comments)

Apply little oil and let it cook
Turn when one side is cooked and let the other side cook too

Remove when crisp

Enjoy with sambhar and chutney