1. Peel off the skin and cut onion into big pieces.
2. Keep other required ingredients ready.
3. Heat oil in kadai/pan and add red chillies, black gram dal, bengal gram dal, tamarind, salt and finally onions. Deep fry them.
4. Allow the mixture to cool, and grind in a mixie.
5. Onion chutney is ready to be served.
6. It can be served with idlys, dosa, chappathi, rice balls.

Note:
Grind the fried onions only after cooling off and add only required amount of water.
Always be careful in adding salt, if it is more we can't eat, if there is no salt we can't imagine of serving. So be patient while adding salt.

Optional: Ingredients can be added or removed according to individuals desire.

This recipe is called Vengaya chutney in Tamil.

Courtesy: http://tamilveg.blogspot.com/