Heat oil in a large saucepan or wok, add chopped green chile and onions. Stir-fry for 5 minutes or until golden brown.
Add curry leaves, ginger-garlic paste, and the dry spice powders. Stir-fry for a minute.
Pour in the fresh tomato puree and cook for 2 to 3 minutes.
Slip in the prawns with 50 milliliters of water and cook for 3 to 4 minutes over high heat. When the liquid has almost evaporated and the prawns are done, serve garnished with fried curry leaves and lemon wedge over 1 cup of cooked rice per person.