Spicy Thai Soup with Prawns and Lemon Grass

Zingy, spicy, clean and refreshing!  This is possibly my favourite soup as it has real impact, its impossible to carry on chatting to your mates when these flavours wallop your tastebuds.  Tom Yam Kung the perfect starter that will make everyone sit up and pay attention.  It's only 5 minutes prep and 5 minutes to cook - a no brainer!

Ingredients
600mls of chicken stock
1 lemon grass stalk, chopped into 4 pieces and bashed to release the flavour
4 kaffir lime leaves, roughly chopped
2 small fresh red chillies, finely sliced
8 button mushrooms, quartered
8 raw king prawns, peeled and deveined
2 tbsp fish sauce
2 tbsp lime juice
1 teasp sugar
Coriander leaves and slices of lime, to garnish.

Method 
In a saucepan, heat the stock to boiling point.  Add the lemon grass, kaffir lime leaves,chillies and mushrooms and bring back to the boil.  Add the prawns, fish sauce, lime juice and sugar and simmer for about a minute or so, until the prawns are cooked.
Turn into soup bowls and garnish with the coriander leaves.