When visiting Koh Samui, don't miss the opportunity to try this spicy and sour soup, prepared with fresh seafood from the Gulf of Thailand.
750 ml chicken stock
1 lemongrass stalk, flattened all the way through
2 kaffir lime leaves, crumpled
60 g galangal, sliced
1 kaffir lime leaf
1 coriander root, lightly crushed
50 g onion, sliced
25 g shallot, sliced
3 tablespoons fish sauce
1 tablespoon roasted chilli paste
1 teaspoon coconut sugar
100 g mushrooms such as oyster mushrooms (cut in half), king oyster mushrooms (sliced), straw mushrooms (cut in half) or shimeji mushrooms
150 g mixed seafood such as prawns (peeled and deveined), squid (cleaned), clams or mussed (cleaned)
2 tablespoons lime juice
2 fresh bird's eye chillies, thinly sliced (optional)
4 cherry tomatoes, halved
3 coriander sprigs, chopped
Bring the chicken stock to the boil. Add the galangal, kaffir leaves, lemongrass, coriander root, onion, shallot, fish sauce, roasted chilli paste and sugar. Simmer over low heat, covered, for 10 minutes.
Add the mushrooms and cook for 2 minutes. Add the seafood and cook for 1 more minute. Add the lime juice then taste to adjust the seasoning.
Remove the galangal, kaffir leaves, lemongrass and coriander root. Add the sliced bird's eye chillies, if using.
Transfer to serving bowls and garnish with tomato and coriander.