Peal the prawns, wash well and drain.

Add 2 tsp of oil, coriander powder and the red chillies to the mustard seeds and grind into a fine paste.

Add oil to a deep bottomed pan and heat. Add the onion paste and fry. Add the onion pieces and fry further.

To the above, add the prawns and turmeric powder. Stir fry well. Add red chilly powder, green chillies, curry leaves, ginger-garlic paste and tomato pieces. Mix well and cook for a couple of minutes.

Add the tamarind pulp, jaggery piece, two glasses of water and salt. Mix thoroughly and cook in medium flame until the prawns are done well.

Finally add the mustard chilly paste to the soup, stir once or twice and remove pan from the stove.

Top the soup with finely chopped coriander leaves and serve hot with rice.