Thai Fish Soup (Tom Yum Pla)
This 30-minute Thai fish soup delivers restaurant-quality flavor with a fragrant broth built on lemongrass, galangal, and kaffir lime leaves. Tender white fish simmers in a creamy coconut milk base that's bright, savory, and gently spicy.
Equipment
- Large soup pot or Dutch oven - at least 4-quart capacity
- Sharp chef's knife
- Cutting board
- Wooden spoon or silicone spatula
- Citrus juicer
- Ladle
- Fine-mesh strainer - optional, for clearer broth
- Measuring cups and spoons
Ingredients
- 1.5 lbs firm white fish fillets - 680g, tilapia, cod, snapper, or halibut, cut into 2-inch chunks
- 4 cups chicken or seafood stock - 950ml
- 1 can coconut milk - 13.5 oz / 400ml, full-fat recommended for creamier broth
- 2 stalks lemongrass - bruised and cut into 2-inch pieces
- 1 inch galangal root - 2.5cm piece, sliced into coins (or substitute fresh ginger)
- 6 kaffir lime leaves - torn in half
- 3 shallots - halved
- 4 cloves garlic - smashed
- 3-5 Thai bird's eye chilies - lightly smashed, adjust to your heat preference
- 1 cup mushrooms - 70g, oyster or straw mushrooms work great, or button mushrooms, sliced
- 1 cup cherry tomatoes - 150g, halved
- 3 tablespoons fish sauce - or to taste
- 3 tablespoons fresh lime juice - about 2-3 limes, plus extra wedges for serving
- 1 teaspoon sugar - palm sugar or white sugar
- 2 tablespoons Nam Prik Pao - Thai roasted chili paste, optional but highly recommended
- fresh cilantro - for garnish
- 2 green onions - sliced, for garnish
- steamed jasmine rice - for serving, optional
- rice noodles - for serving, optional
- Thai basil leaves - for garnish, optional
- fresh bean sprouts - for serving, optional
Instructions
- Prep aromatics: Trim lemongrass, bruise, and cut into 2-inch pieces. Slice galangal into coins, tear kaffir lime leaves, halve shallots, smash garlic, and lightly smash chilies. Cut fish into 2-inch chunks and pat dry.
- Pour stock into a large pot. Add lemongrass, galangal, kaffir lime leaves, shallots, garlic, and chilies. Bring to a gentle boil, then reduce to a simmer and infuse for 15 minutes.
- Stir in coconut milk, fish sauce, lime juice, sugar, and Nam Prik Pao if using. Bring back to a gentle simmer. Taste and adjust seasoning.
- Add mushrooms and simmer for 3-4 minutes until tender. Add cherry tomatoes and simmer for 2 more minutes.
- Gently slide fish pieces into the broth in a single layer. Reduce heat to medium-low and cook for 3-5 minutes until fish is opaque and flakes easily.
- Taste one final time and adjust seasoning. Ladle into bowls and garnish with cilantro, green onions, and extra lime wedges. Serve immediately over rice or noodles if desired.
Notes
- Bruise, don't chop: Bruising lemongrass, galangal, and kaffir lime leaves releases their essential oils without making the broth cloudy or leaving fibrous pieces that are unpleasant to bite into.
- Use full-fat coconut milk: Low-fat coconut milk produces a thinner, less rich broth. The fat in full-fat coconut milk carries the aromatic flavors and gives the soup its beautiful body.
- Don't overcook the fish: Fish needs only 3-5 minutes in simmering broth. Set a timer and check it early. Overcooked fish becomes tough and dry.
- Season in layers: Add fish sauce, lime juice, and sugar before the fish goes in, taste the broth, and adjust. Then taste again after the fish cooks and do a final adjustment.
- Add lime juice off the heat: Lime juice can turn bitter if boiled for too long. For maximum brightness, stir in a last squeeze of fresh lime juice just before serving with the heat off.
- Use quality fish sauce: A good Thai fish sauce (Tiparos, Megachef, or Tra Chang) gives the soup its savory depth without harsh saltiness.
- Pat the fish dry: Removing excess moisture from the fish before adding it to the broth helps it stay intact rather than becoming waterlogged and falling apart.
- Storage: Store leftover soup in an airtight container in the refrigerator for up to 2 days. Freeze the broth separately without the fish for up to 1 month.
- No coconut milk version: Skip the coconut milk entirely and increase the stock to 5 cups (1.2 liters) for a lighter, more intensely sour broth closer to classic Tom Yum Pla.
- Make ahead: The broth can be made up to 2 days in advance. When ready to serve, bring the broth back to a gentle simmer, add the mushrooms, tomatoes, and fish, and finish the recipe from Step 4.