House Favourite Tom Yum Recipe

Prepare aromatics

Peel and crush the shallots and garlic lightly with the flat side of a knife. Trim the lemongrass: remove outer dry layers, bruise the stalks by hitting with the back of a knife and slice each stalk into 3-4 pieces. Slice the galangal into 3–4 thin rounds. Stack kaffir lime leaves and roll, then thinly slice (or tear) to release oils.

In a medium saucepan, combine 1200 ml water and 400 ml stock and bring to a gentle simmer over medium heat.

Add the prepared lemongrass, galangal, crushed shallots and garlic, and kaffir lime leaves to the pot. Reduce heat to low and simmer gently, uncovered, for 12–15 minutes to infuse the broth. Keep at a bare simmer — do not rapidly boil to preserve the aromatics’ bright flavors.

While the broth infuses, prepare the chilies: bruise the bird's eye chilies with the side of a knife (split if you prefer more heat). If you want milder soup, remove the seeds.

After the broth has infused for 12–15 minutes, strain out the large pieces of lemongrass and galangal with a slotted spoon or fine sieve, leaving the aromatic-flavored liquid in the pot.

Return the pot to medium-low heat. Stir in 1 tablespoon nam prik pao (optional) and simmer 1 minute to meld. Add fish sauce, 1 tsp sugar, and the bruised chilies. Taste and adjust seasoning — it should be a balance of salty (fish sauce), sour (lime) and a touch of sweetness.

Remove the pot from heat, then stir in the 45 ml fresh lime juice. (Alternatively add most of the lime juice at the end after cooking prawns to preserve brightness; see next section.)

Bring the seasoned broth back to a gentle simmer. Add the halved mushrooms and cherry tomatoes (if using). Simmer 2–3 minutes until mushrooms begin to soften.

Add the tiger prawns to the simmering broth and cook 2–3 minutes until prawns turn opaque and curl. Do not overcook — prawns cook quickly.

Once prawns are cooked, reduce heat to low and gently stir in 200 ml coconut milk. Warm through for 1 minute without boiling (to prevent coconut milk splitting). Taste and adjust seasoning: add more fish sauce for salt, more lime juice for sourness, or more sugar for balance.

Ladle the soup into warmed bowls, ensuring each bowl gets prawns, mushrooms and an even amount of broth.

Garnish with sliced spring onions, chopped coriander leaves, and extra torn kaffir lime leaf if desired. Serve with lime wedges on the side for individual adjustment of sourness.

Serve immediately as a starter while hot. Recommended accompaniment: steamed jasmine rice or a light finger plate.