Seafood Tom Yum Soup Recipe

Prepare aromatics

Smash the lemongrass stalks lightly with the side of a knife and cut into 2–3 segments. Tear the kaffir lime leaves (or bruise them) to release oils. Slice galangal into rounds. Halve the shallot.

In a 4–5 quart pot, bring 6 cups water or stock to a gentle boil over medium-high heat. Add the prepared lemongrass, galangal, kaffir lime leaves, and halved shallot. Reduce heat to medium-low and simmer uncovered for 10–12 minutes to infuse the broth.

While the broth simmers, lightly smash the chilies and garlic with the flat side of a knife. If you prefer less heat, remove seeds from chilies before smashing.

After 10–12 minutes of simmering, add the smashed chilies and garlic to the pot. If using tom yum paste, stir in 1 tablespoon now and simmer 2–3 more minutes to incorporate.

Season the broth with 2 tablespoons fish sauce and 1 teaspoon palm sugar. Taste and adjust: tom yum should be a balance of spicy, salty, sour, and slightly sweet. Don’t add lime juice yet — add it at the end for the brightest flavor.

Add the sliced carrots, onion, and mushrooms (and optional cherry tomatoes) to the simmering broth. Cook until vegetables are tender-crisp, about 3–4 minutes.

Increase the heat to bring the broth to a gentle boil. Add mussels first, cover the pot, and cook for 3 minutes to allow them to open. Discard any mussels that remain closed after 3–4 minutes.

Add the shrimp and calamari rings and simmer uncovered for an additional 2–3 minutes, or until shrimp turn pink and curl and calamari is just opaque and tender. Avoid overcooking the seafood to keep it tender.

Turn off the heat. Remove and discard the larger pieces of lemongrass, galangal, kaffir lime leaves, and shallot if desired for easier eating (or leave in for presentation).

Stir in 3 tablespoons fresh lime juice. Taste and adjust seasoning with additional fish sauce (1/2 teaspoon at a time) or lime juice to reach your preferred balance.

Ladle the soup into bowls, making sure each serving gets a mix of shrimp, calamari, mussels, vegetables and broth. Garnish with chopped cilantro, sliced scallions, Thai basil leaves if using, and serve with lime wedges on the side.