1. Add some oil in a vessel.
2. Fry some onions and green chillies.
3. Pressure cook the lotus stem with water until one whistle.
4. Break the vadi into the fried onion mixture. Add the potatoes.
5. Put the cooked lotus stem in the potato and onion mixture.
6. Add all the dry spices and mix well.
7. Put tomatoes and coriander leaves.
8. Pour some hot water and cover and cook.
9. Serve warm.