1. Peel off all but the tails of the shrimps, and then wash thoroughly.
2. Fry in hot mustard oil till brown. Take out and keep aside.
3. Wash the pui sag and separate the leaves from the stems.
4. Cut the stems into 2 inch bits and fry in the mustard oil for about 2 minutes.
5. Drain and discard the oil. Grind to a paste the mustard seeds and red chili.
6. Heat some oil in a saucepan and when smoking hot, put in the stems of pui sag and the leaves.
7. Fry for a minute, then put in the paste and turmeric and continue frying till water oozes out from the saag.
8. Finally, add the shrimps and salt, and cook for another 5 minutes.
9. Remove from heat and serve hot.