Marinate the prawns with lime juice, salt, chilly powder and turmeric powder. Keep it aside for half an hour.
Heat oil in a pan, add ginger and garlic pastes. Saute for some time. Add curry leaves, onion and green chillies. Saute well. Add chilly powder and coriander powder. Stir well in low flame.
Add marinated prawns into it and cover with a lid till prawns are cooked well.
After that, add garam masala and a little lime juice. Don't add water since this is a dry prawn recipe.