Method

• Blend the ginger and garlic together in a food processor to make a fine paste. Remove and set aside, then blend the onions to a fine paste with 100ml of the oil.
  
  Season the prawns with 1/2 teaspoon each of the turmeric and salt. Heat 2 tablespoons of the oil in a non-stick frying pan and sear the prawns briefly, then remove and set aside.
  
  Heat the remaining oil in a heavy frying pan and add the onion paste with the cinnamon leaves.
  
  Fry over a moderate heat for 10 minutes or until light brown, stirring occasionally.
  
  Mix together the cumin, remaining turmeric, ginger-garlic paste and 150ml water, then add to the onions.
  
  Reduce the heat and cook for another 5-8 minutes, stirring regularly. Stir in the remaining salt, the green chillies and prawns and continue cooking for 2-3 minutes.
  
  Mix in the coconut milk and simmer for 2-3 minutes or until the prawns are just cooked, adding a little more water if necessary.
  
  Correct the seasoning with salt and sugar, sprinkle over the cardamom seeds and stir in the clarified butter.
  
  Serve with steamed rice.