Tom Yum Soup Recipe

Prepare aromatics

Trim outer tough layers from lemongrass, smash the stalks lightly with the back of a knife and cut into 2-inch pieces. Thinly slice galangal (or ginger). Tear kaffir lime leaves to release oils. Halve the shallot.

In a medium-large saucepan, combine 6 cups water or low-sodium chicken stock with the prepared lemongrass, galangal, kaffir lime leaves, and shallot. Bring to a gentle boil over medium-high heat.

Once boiling, reduce heat to a simmer and cook uncovered for 10 minutes to infuse the broth with aromatics.

After simmering 10 minutes, skim any foam from the surface. Add 1 tablespoon Nam prik pao (or sambal) and stir until dissolved into the broth. Taste and adjust amount for desired heat and sweetness.

Add 3 tablespoons fish sauce, 1 teaspoon sugar, and 1/2 teaspoon salt. Stir and simmer 2 minutes to meld flavors.

Add the sliced mushrooms to the simmering broth and cook 2–3 minutes until they begin to soften.

Add the tomato wedges and continue simmering 1–2 minutes to warm them but retain some texture.

If using shrimp: turn heat up slightly so broth is gently bubbling and add the shrimp. Cook 2–3 minutes until shrimp are opaque and just cooked through. If using thin-sliced chicken: add the chicken and poach 3–4 minutes until cooked through.

Taste the soup and adjust seasoning now: add more fish sauce for saltiness or a little sugar if too sour/spicy.

Remove the pot from heat. Stir in 3 tablespoons fresh lime juice and 1/4 teaspoon ground white pepper. Add the chopped scallion green parts and smashed/sliced Thai chilies (start with 1–2 chilies and add more to taste).

Ladle soup into bowls, garnish with cilantro leaves, and serve immediately with extra lime wedges and chili paste on the side if desired.