Spicy Tom Yum Soup Recipe

Prepare aromatics

Smash the lemongrass stalks with the back of a knife and cut into 2–3 pieces each. Lightly smash the garlic and halved shallot. Thinly slice galangal. Tear the kaffir lime leaves once to release oils. Slightly crush the chilies (keep seeds if you want more heat).

Simmer broth

In a large pot, bring 6 cups water or stock to a gentle boil over medium-high heat. Add lemongrass, galangal, kaffir lime leaves, shallot, garlic and chilies. Reduce heat to medium-low and simmer, uncovered, for 10–12 minutes to infuse the broth. Taste the aromatics — they should smell bright and spicy.

After 10–12 minutes, strain the broth through a fine-mesh sieve into a clean pot to remove the large aromatics, or leave them in if you prefer a rustic presentation. Return the clear broth to medium heat and add fish sauce, palm sugar (or brown sugar), and the optional Thai roasted chili paste. Stir to dissolve and balance salty, sweet and savory flavors.

Turn off the heat briefly, then stir in the fresh lime juice. Taste and adjust: add more fish sauce for saltiness, more lime for acidity, or another ½–1 tsp sugar if it's too sour. Keep the broth hot but not boiling once adjusted.

Bring the seasoned broth back to a gentle simmer (small bubbles). Add the sliced shiitake mushrooms and optional straw/button mushrooms. Simmer 2–3 minutes until mushrooms begin to soften.

Add the white fish pieces first and simmer 1–2 minutes (depending on thickness) until they are just opaque. Then add scallops and shrimp and simmer another 2–3 minutes until shrimp turn pink and scallops are cooked through. Do not overcook — total cooking time for seafood should be about 3–5 minutes depending on size.

Add the tomato wedges and sliced green onions to the pot and simmer 1 minute to warm without breaking down the tomato. Turn off heat.

Ladle the soup into bowls, distributing shrimp, scallops, fish, mushrooms and tomatoes evenly. Sprinkle chopped cilantro over each bowl. Serve immediately with lime wedges on the side for extra acidity and steamed jasmine rice if desired.