Firstly marinate the prawns with 1/2 tsp turmeric powder and some salt and keep it asidefor 5 mins.
Now soak the saffron in 1/2 cup of hot water and keep it aside for later use.
Heat 2 tbsp of oil in a large deep pan/kadhai on medium heat. When hot add the prawns and fry until the prawns just changes colour. This shouldn't take more than a minute. Take it off the pan with a skimmer and keep it aside.
Add the rest of the oil in the same pan and add the bay leaves, cinnamon, cardamoms, cloves and saute for 10-20 seconds or until you get the aroma of the spices.
Now toss in the garlic along with the chopped onions and saute on medium heat until it is soft and translucent.
Add the Ginger garlic paste and continue sauteing until the raw smell disappears.
Add the chilli powder, turmeric powder, cumin powder, coriander powder along with some salt and saute for 20-30 seconds.
Then add the chopped tomato and mix everything well with the masala.
Saute on medium heat until the tomatoes are soft and mushy and you can see some oil seeping through the sides.
Pour in the coconut milk along with the saffron water and stir it well with the masala. Cover and cook on low heat for 5-6 minutes.
Finally toss in the prawns and mix everything well. Cover and cook for 2-3 minutes. DO not cook prawns for longer period of time it makes them tough and rubbery.
Finally add chopped coriander leaves and take it off the heat.
Serve it hot with hot steaming rice.