Marinate the the cleaned and de-veined prawns in some salt, 1 tsp chilli powder, coriander powder and turmeric. Set aside for 5 minutes.
Place a pan with coconut oil on medium heat and add the sliced onions. Saute for 2-3 minutes till the onions start to caramelize slightly.
Now add the ginger, garlic and green chillies. Saute and cook for a further 3-4 minutes.
Now tip in the prawns and chopped curry leaves and mix well with the onion masala. Continue to cook for 10-12 minutes, stirring intermittently. The prawns will release some moisture. Allow the water to dry so that the spice paste has a thick, coating consistency.
Once the prawns are cooked and the masala coats them, check and correct the seasoning, add the ground pepper, cinnamon, clove and fennel seed. Mix well.
Toss in the remaining whole curry leaves, sprinkle the rice powder over, mix thoroughly and quickly stir fry on a high flame for a minute. Turn off the heat and serve hot.