Tom Yum Soup Recipe

Crush the lemongrass stalks a few times with the flat side of a knife and trim tough ends. Slice the stalks into 2–3 pieces each. Peel and thinly slice the galangal. Lightly crush the shallot and smash the garlic cloves.

In a medium-large pot, bring 6 cups of water or low-sodium chicken stock to a gentle boil over medium-high heat.

Add the prepared lemongrass, galangal, kaffir lime leaves (torn if large), shallot, garlic and the whole bird's eye chilies to the pot. Reduce heat to medium-low and simmer, partially covered, for 10–12 minutes to infuse the broth.

While the broth simmers, clean and halve the mushrooms if large. Trim pak choi: separate leaves, wash thoroughly, and cut any large stems into 1–2 inch pieces.

After 10–12 minutes, strain the broth through a fine-mesh sieve into a clean pot or return the solids to the pot and remove the aromatics with a slotted spoon (discard solids). Bring the strained broth back to a gentle simmer.

Add the mushrooms to the simmering broth and cook for 2–3 minutes until softened.

Add the pak choi stems first and simmer 1–2 minutes, then add the leaves and cook for another 1 minute until bright green and tender-crisp.

Stir in fish sauce, sugar, and the nam prik pao (if using). Taste the broth and adjust seasoning—add more fish sauce for saltiness or a pinch more sugar if too sour.

Remove the pot from heat for the acid step: stir in the fresh lime juice. Taste and add additional lime if you prefer a brighter, tangier soup.

With the broth off the heat but hot, add the peeled prawns. Let them sit in the hot broth for 2–3 minutes until they turn opaque and curl (do not overcook). If you prefer, briefly return to very low heat for 30–60 seconds while stirring.

Taste again and adjust seasoning (lime, fish sauce, or a pinch of sugar) as needed.

Ladle the soup into bowls, dividing prawns, mushrooms and pak choi evenly. Garnish each bowl with chopped cilantro, sliced spring onions, and thin red chili slices to taste.

Serve immediately with lime wedges on the side for extra acidity.