Tom Yam Soup - Prawns Recipe

Prepare aromatics

Smash the lemongrass stalks with the butt of a knife or rolling pin to bruise and release oils; cut into 2-inch pieces. Peel and halve shallots. Slice galangal into 1/8–1/4-inch rounds. Tear kaffir lime leaves to release fragrance. Crush chilies lightly (wear gloves if desired).

In a medium-large pot, heat 1 tablespoon vegetable oil over medium heat. Add shallots and crushed chilies and sauté for about 30–45 seconds until fragrant (do not brown).

Add 6 cups water or light chicken stock to the pot. Add sliced galangal, smashed lemongrass pieces, and torn kaffir lime leaves. Bring to a gentle boil, then reduce heat to maintain a simmer. Simmer uncovered for 8–10 minutes to infuse the broth with aromatics.

While the broth simmers, clean and devein prawns if not already done. Halve mushrooms and tomatoes. Slice green onions and pick roughly chopped cilantro leaves for garnish.

After the broth has simmered 8–10 minutes, add mushrooms and cherry tomatoes. Continue simmering for 2–3 minutes until mushrooms begin to soften.

Add the prawns to the simmering broth. Cook until prawns turn pink and opaque—about 2–3 minutes depending on size. Do not overcook; prawns cook quickly.

Remove the pot from heat (or reduce to the lowest setting) and immediately stir in 3 tablespoons fish sauce and 3 tablespoons fresh lime juice. Taste and adjust balance: add up to 1 teaspoon sugar if too sour or salty, a little more fish sauce for saltiness, or more lime juice for brightness. If using Nam Prik Pao, stir in 1 tablespoon now; it will add sweetness, smokiness, and color.

If you prefer a creamy Tom Yum (Tom Yum Nam Khon), stir in up to 1 cup evaporated milk or coconut milk now and gently warm through without boiling. Heating too rapidly may curdle evaporated milk.

Skim out and discard large pieces of galangal, lemongrass, and kaffir lime leaves (or leave in for presentation if diners will remove them). Adjust seasoning one more time.

Ladle soup into bowls, garnish with chopped cilantro and sliced green onions, and serve immediately with additional lime wedges and extra chilies or fish sauce at the table.