For the original recipe and instructions, see: "Tom Yum Soup (Thai Soup)" at recipetineats.com
Lemongrass - To prepare, cut in half, peel the reedy green shell to reveal the softer white part on the bottom half of the lemongrass. If lemongrass is hard to come by, you can use PASTE: stir in 1 tbsp.
Galangal is like ginger but it has a more sour and peppery flavour. If you can't find it, just substitute ginger and a grind of black pepper.
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