This is a delicious tom yum-style Thai soup with noodles, which can be served several ways. You can, if you like, strain the bits and pieces out of the broth, but the more authentic way of serving it is to leave them in. And you could replace the prawns with shredded chicken. As a matter of fact, barbecue pork (from your local Chinatown) would taste pretty damn good in this soup, too.
6 cups chicken stock
2 stalks lemongrass, trimmed, cut into 2cm lengths and crushed
7 slices galangal, crushed
5 makrut lime leaves, crushed in your hand
4 tbsp store-bought chilli paste
8 green bird's-eye chillies, chopped
2 tbsp palm sugar
5 tbsp fish sauce
8 large cooked king prawns, shelled and de-veined
10 oyster mushrooms, halved
juice of 4 limes
400g fine egg noodles
4 sprigs coriander, roughly chopped
2 shallots (spring onions), green and white parts, cut into rounds
1. Heat stock in a pot until boiling. Add the lemongrass, galangal, lime leaves and chilli paste. Season to taste with chopped chilli, palm sugar and fish sauce. Add the prawns and mushrooms. Simmer for 5 minutes, then remove from heat. Add the lime juice and check the taste – the soup should be sour but balanced, and fiery hot.
2. Bring a large pot of water to the boil and salt heavily. When boiling, add the noodles and stir so they don't stick. Cook for about 1-1½ minutes. Pour the noodles out into a colander in the sink.
3. Divide the noodles among 4 large soup bowls, and ladle the soup with a couple of prawns and a quarter of the mushroom for each bowl. Sprinkle with coriander and shallot, and serve.