Tom Yum Goong

Tom yum goong is Thailand's hot and sour shrimp soup, its broth built on lemongrass, galangal and kaffir lime leaf and sharpened with lime juice and chilli.

What it really is

The broth starts as water or a light shrimp stock, brought to a boil with bruised lemongrass, sliced galangal and torn kaffir lime leaves — the three aromatics that give tom yum its character before any chilli or lime goes in. Shrimp and straw mushrooms go into the pot, often with the shrimp shells and heads simmered first for extra flavour; fish sauce, chilli and a generous squeeze of lime juice are stirred in at the end, off the heat, so the sourness stays sharp rather than boiling flat.

No single flavour is allowed to lead — sour, salty, spicy and only faintly sweet, all at once. Two versions are common on menus: tom yum nam sai keeps the broth clear, while tom yum nam khon is enriched with roasted chilli paste and sometimes coconut milk or evaporated milk for a creamier, orange-red broth. Coriander leaves go on top just before the bowl leaves the kitchen.

How it is served

• Hot, in a shared pot or individual bowls, alongside rice and other dishes rather than on its own.
• With the lemongrass stalks, galangal slices and lime leaves left whole in the bowl — pushed aside, not eaten.
• With extra chilli or lime on the side for guests who want it sharper.

How to write it on the menu

• Say whether the broth is the clear nam sai or the richer, chilli-paste nam khon version; regulars will ask.
• Shrimp and fish sauce make the classic version neither vegetarian nor vegan; a mushroom broth with soy sauce is the usual substitution.
• Note that the lemongrass, galangal and lime leaves are aromatics, not meant to be eaten, if guests are new to the dish.