Clean the prawns and remove their veins.
Marinate them with little chilly powder, turmeric powder, salt, lemon juice and garlic paste and keep for 1 hour.
After one hour, cook the prawns in little water, till they are 3/4th done.
Heat 2 tbsp of butter in a nonstick pan.
Add potatoes into it and fry them till they are fully cooked.
Smash the cooked potatoes and keep aside.
Heat 1 tsp of butter and 2 tsp of oil in a pan.
Add curry leaves, onion and ginger-garlic paste and saute till they are golden brown.
Add chilly powder, turmeric powder, coriander powder and garam masala and mix well.
Add tomatoes and tomato sauce and stir till the tomatoes are done.
Add the smashed potatoes and prawns along with little water.
Simmer in low heat for 5 or 10 min.
:- Serve hot with roti or rice.
:- You can also add scrambled eggs to the curry to improce the taste.