Tom Yum Soup Recipe

Prepare aromatics

Trim the lemongrass: remove dry outer layers and bash the stalks with the back of a knife, then slice into 2-inch pieces. Smash the shallot and garlic lightly to release oils. Rinse kaffir lime leaves and tear each leaf once to release aroma. Slice galangal into 4 thin coins if not already.

In a large pot, combine 6 cups chicken or vegetable stock and 1 cup water. Add the prepared lemongrass, galangal slices, kaffir lime leaves, smashed shallot, and smashed garlic. Bring to a gentle simmer over medium heat.

Simmer gently, uncovered, for 12–15 minutes to infuse the broth. Do not boil vigorously — maintain a gentle simmer so the aromatics release flavor without clouding the soup.

While the broth simmers, clean and prepare mushrooms (halve larger ones or slice if needed). If using shrimp, pat them dry and season lightly with a pinch of salt. If using tofu, cut into 1/2-inch cubes and set aside.

After 12–15 minutes of simmering, strain the broth into a clean pot or remove large pieces of aromatics with a slotted spoon, leaving the infused broth. Return the broth to medium heat and bring it back to a gentle simmer.

Add the mushrooms to the simmering broth and cook for 3–4 minutes until tender. If using tofu, add it with the mushrooms so it warms through.

If using shrimp, add them in the last 2–3 minutes of cooking. Shrimp cook quickly and are done when they turn pink and opaque (about 2–3 minutes depending on size).

Crush or finely slice the bird's eye chilies. If you prefer less heat, remove the seeds. Add the chilies to the pot along with 1 tablespoon Thai chili paste (nam prik pao) or sambal for depth and color.

Stir in 3 tablespoons fish sauce and 1 teaspoon sea salt. Taste the broth and adjust seasoning — fish sauce adds saltiness and umami; add more if needed, 1/2-tablespoon at a time.

Remove the pot from heat. Stir in 3 tablespoons fresh lime juice gradually, tasting as you go to reach the desired balance of sourness. If the soup is too sharp, add up to 1 teaspoon sugar to balance.

Ladle the soup into bowls. Garnish with chopped cilantro and sliced green onions. Serve immediately while hot and aromatic.