Tom Yum Recipe

Prepare aromatics

Trim and smash the lemongrass stalks with the back of a knife and cut into 2–3 pieces. Slice the galangal into 1/8–1/4-inch rounds. Lightly bruise the kaffir lime leaves by folding them in half and rubbing between your palms. Peel and halve the shallot. If you prefer milder heat, halve or lightly bruise the bird's eye chilies; leave whole for more heat.

In a large pot, bring 6 cups of water or low-sodium chicken stock to a gentle boil over medium-high heat.

Add the prepared lemongrass, galangal, kaffir lime leaves, shallot and whole chilies to the pot. Reduce heat to medium-low and simmer, uncovered, for 10–12 minutes to infuse the liquid with aromatics.

After simmering, use a slotted spoon to remove and discard or reserve the larger aromatics (lemongrass and galangal are fibrous and usually removed). Keep the infused broth simmering gently.

Add the tomato wedges and halved mushrooms to the simmering broth. Continue simmering 3–4 minutes until tomatoes soften and mushrooms begin to release liquid.

If using chicken, add thinly sliced chicken now and simmer 3–4 minutes until cooked through (no pink remains). If using shrimp, add shrimp after the tomatoes and mushrooms have softened — simmer 2–3 minutes until shrimp turn pink and opaque. Do not overcook shrimp.

Stir in fish sauce and palm sugar (or brown sugar), taste and adjust saltiness. The soup should be a balance of savory (fish sauce), sour (lime), spicy (chilies) and a touch of sweetness.

Remove the pot from heat. Stir in fresh lime juice and chili oil or a spoonful of nam prik pao to add color and depth; start with 1 tablespoon and add more to taste.

Add chopped cilantro and sliced green onions; stir briefly. If using Thai basil, add it last so it wilts lightly but retains flavor.

Ladle the soup into bowls and garnish with additional cilantro leaves and a wedge of lime if desired. Serve immediately while hot.