To make the masala, in a food processor, add the onion, garlic, ginger and 1 handful of coriander. Grind to a coarse paste.
In a pan, heat the olive oil. Once hot, add the cardamom, cumin seeds and the lemon grass stalk. Once they begin to sizzle, add the grinded masala paste. Mix well and add the salt, turmeric powder, chilli powder and garam masala. Mix on high heat for 10 minutes, constantly stirring.
When the oil separates from the masala, add the fresh and plum tomatoes. Mash together well and cook for a firther 7 minutes.
Add the prawns at this point and mix together on high heat. Stir continuously for 10 minutes.
Add 1/4 cup water and reduce the heat to the lowest setting.
Add the sour cream and another handful of coriander. Stir.
Turn the heat off and place the lid on the pan tightly. Let it cook in its own heat for 5 minutes.
Balle Balle! You are ready to CHOW DOWN. Best served with hot hot chappatis. For more Indian Recipes, you can check out my blog www.balleindianfood.com :)