Nadan Konju/Chemmen curry [Kerala Style Prawns curry]

Prawns - 1lb or 1/2 kg
small onion or shallots- a handful
tomato - 1
ginger and garlic - 1 tbsp crushed
kudam puli(kerala fish tamarind) - 2 pieces

fenugreek powder - 1/2 tsp
turmeric powder - 1/2 tsp
kashmiri chilli powder - 2 to 3 tsp
coriander powder - 1 to 2 tsp

curry leaves -  1 sprig
oil -  1 tbsp
mustard seeds - 1/2 tsp

Clean prawns and keep.
Heat oil. Splutter mustard. Add curry leaves.
Add small onions, followed by crushed ginger and garlic and saute for a minute.
Now add all powders and saute well until you get a roasted masala smell.
Add chopped tomatoes and saute for a minute.
Add the soaked kudam puli and 1 and a half cups of water and boil nicely.
Add the prawns and cook for 3 to 5 minutes.
To keep the prawns soft itself try not to overcook them.
Done.