Grind the mustard seeds with 1 - 2 green chillies, coconut and little water. Keep aside.
Smear the prawns with little salt and turmeric and keep covered.
Heat the oil and add 1 - 2 green chilli slited when splutter add the prawns. Saute on low for a couple of minutes or till the prawns turn a little coral in colour.
Add the grated raw mango and a pinch of salt. Keep mixing with a very light hand till the raw smell of the mango are gone (approx 2 minutes).
Add the mustard paste and turmeric, give it a good mix and cook on low till it coats the prawns.
Add 1cup of milk, mix add sugar and salt if required chilli powder. Cover and let it simmer on low till all the milk evaporated and the gravy coats the prawns.
Serve hot or at room temperature with hot steamed white rice.
Enjoy a sensational hot - sweet - spicy taste with every morsel.....
