Remove the skin of the raw mango and slice it into medium pieces.
Heat raw mango, sliced onions, tomatoes, ginger, garlic, green chillies, tumeric powder and chilly powder with enough water in a pan(preferably Kalchatti).
Once the mangoes turn slightly soft, add the prawns and salt.
Cook for some time and add the seasoning given below.
Optional:- Grind together coconut, cumin seeds and shallots into a paste with some water and add it to the curry and allow it to boil.