Clean the prawn thoroughly and cook them along with turmeric in a pan. The prawns will give out water on it's own. Cook till all the water is dried up from the prawns. Once the water is dried up, switch off the flame.
Lightly dry roast the cumin seeds, coriander seeds, black pepper corns, fennel seeds and make it to a fine powder in a dry grinder.
Heat oil in a non stick pan and add the curry leaves.
Now add the ginger garlic paste and fry on low heat till the raw smell vanishes.
Throw in the prawns and fry for another couple of minutes. Do not over fry as the prawns will become hard if you overcook it.
Toss in the ground spice powder, red chili powder, garam masala powder, salt and mix in well.
If necessary add in some water to prevent the masala from getting burnt.
When the raw smell from the masala has gone, switch off the flame and serve hot.