Tom Yum Soup Recipe

Prepare aromatics

Smash the lemongrass stalks with the back of a knife and cut into 2–3 pieces each. Peel and thinly slice the galangal. Lightly bruise the kaffir lime leaves by folding them once. Slice shallots in half. If you prefer less heat, halve and seed the chilies; otherwise leave whole.

In a large pot, combine 6 cups stock and 1 cup water. Add the prepared lemongrass, sliced galangal, kaffir lime leaves, shallots, and whole chilies. Bring to a gentle boil over medium-high heat.

Once boiling, reduce heat to a simmer and cook uncovered for 10–12 minutes to infuse the broth. Taste for balance — the aromatics should be prominent but not overpowering.

While the broth simmers, prepare the shrimp: if frozen, thaw, peel and devein. Pat dry. Clean and slice mushrooms and cut the tomato into wedges.

After the 10–12 minute infusion, add the mushrooms and tomato wedges to the simmering broth. Continue simmering for 3–4 minutes until mushrooms begin to soften.

Add the shrimp to the pot and simmer gently for 2–3 minutes, until the shrimp turn pink and opaque. Do not overcook — shrimp cook quickly.

In a small pan or the same pot off heat, warm 1 teaspoon vegetable oil and add 1 tablespoon Nam Prik Pao (if using). Stir briefly to bloom the paste (30 seconds). Add this to the soup and stir to incorporate.

Stir in 3 tablespoons fish sauce, 1 tablespoon tamarind paste, and 1 teaspoon sugar. Taste the broth and adjust: add more fish sauce for saltiness, more lime for acidity, or a pinch more sugar if too sour.

Remove the pot from heat. Stir in 3 tablespoons fresh lime juice. Add 1/2 teaspoon salt only if needed (fish sauce already salty).

Ladle soup into bowls. Scatter Thai basil or cilantro leaves on top (about 1 cup divided among servings). Serve immediately with extra lime wedges and chili on the side.