sambal prawn

for cooking sambal prawn has many different way.. but I try one of this recipe from my friend, she's a good cook. she can make a dish with many art of cooking.
Ingredients:
1 200g pack king prawns
1 medium sized onion
3/4 inch fresh root ginger
2 garlic
3-4 fresh red chillies
2-3 tomatoes
1-2 candlenuts
1/2 inch belacan (shrimp paste)
1 tbsp chilli powder
coconut cream or half a can of coconut milk
2-3 tbsp tamarind juice
stalk lemon grass
sugar
salt
cooking oil

Method
Wash the prawns and drain off excess water
Slice the onion thickly
slice the fresh root ginger thickly
Cut the garlic into thick slices
Chop the fresh red chillies (remove seeds for a milder taste)
Cut the tomatoes into quarters
the candle nuts roughly
Add the belacan with these ingredients
Put all the ingredients in except the prawns into the blender and blend
Remove and place in a bowl ( if you don't have any blender use "lumpang")
Heat some cooking oil in a wok
When hot, put the blended ingredients in the oil and stir over a medium heat until fragrant
Add the lemon grass and cook for a further 2-3 minutes
Now add the chilli powder, coconut cream/milk and tamarind juice
Put in the king prawns
Continue to cook over a gentle flame
Add salt and sugar as you like
Mix well and remove from heat