1. Shell the prawns, devein and clean them. drain the water.
2. To make the masala paste, make thick slices of the onion and tomatoes, peel the ginger & garlic and chop the ginger. cut the green chillies.
3. Now heat 1.5 tbsp oil in a pan and add the cumin seeds. give a stir and then add the onion slices. fry on medium heat for 3 mins till the onions become translucent.
4. Now add the ginger, garlic and green chillies, give a mix and fry on medium heat for 2 mins.
5. Lastly add the tomato slices, give a mix and continue to fry on medium heat for 3 mins till the tomatoes are soft. set aside on a plate and allow to cool.
6. Once cooled, add the mix to a grinder/blender and blend it to a paste after adding 2 tbsp water.
7. Fine chop the coriander leaves and set aside.
8. Heat oil in a wok or kadhai. now add the masala paste (made above) and fry on medium heat for 3 mins.
9. Add all the spice powders other than garam masala powder and 1/2 tsp salt, give a mix and fry on medium heat for another 5 mins adding a splash of water whenever required. fry till oil separates.
10. Now add the prawns, garam masala powder and 1 tsp salt, give a mix and fry/bhunno on medium heat for 3 mins.
11. Add 200 ml water, give a mix and cover & cook on low heat for 7 mins till the prawns and the gravy are cooked and oil separates.
12. Garnish with finely chopped coriander leaves, mix and serve.