Southern Thai Gaeng Som Sour Curry with Fish

Why You’ll Love This Recipe

• True southern-style gaeng som: no coconut milk, vibrant turmeric color, and bracing tamarind tang.
• Light yet satisfying—lean fish and chunky vegetables in a clean, aromatic broth.
• Weeknight-friendly: from pantry to bowl in under an hour.
• Customizable heat level and vegetables—use green papaya for classic texture or daikon for convenience.

Grocery List

• Produce: Green papaya or daikon radish, long beans or green beans, shallots, garlic, fresh turmeric (or ground), limes, cilantro or sawtooth herb.
• Dairy: None.
• Pantry: Dried Thai chiles, shrimp paste (kapi), tamarind concentrate or pulp, fish sauce, palm sugar, kosher salt, firm white fish (cod, snapper, halibut), jasmine rice.

Full Ingredients

Curry Paste

• 8–10 dried Thai chiles (10–12 g), stems removed, soaked in hot water 10 minutes
• 3 small shallots (about 90 g), roughly chopped
• 4 garlic cloves, roughly chopped
• 1 tbsp finely grated fresh turmeric (or 1½ tsp ground turmeric)
• 1 tsp shrimp paste (kapi)
• ¾ tsp kosher salt
• 1–2 tbsp chile soaking water (as needed for blending)

Broth & Seasonings

• 4 cups (960 ml) water or light fish stock
• 3 tbsp (45 ml) tamarind concentrate, or 45 g tamarind pulp soaked and strained
• 2 tbsp fish sauce, plus more to taste
• 1 tsp palm sugar (or light brown sugar), plus more to taste
• Optional: 1/8 tsp white pepper

Fish & Vegetables

• 1¼ lb (560 g) firm white fish (cod, snapper, halibut), cut into 2-inch pieces, patted dry
• 1 lb (450–500 g) green papaya (peeled, seeded) or daikon radish, cut into ¾–1 inch chunks
• 6 oz (170 g) long beans or green beans, cut into 2-inch pieces
• Optional add-ins: 1 small tomato cut into wedges or 1 cup (150 g) pineapple chunks

To Serve

• Lime wedges
• Cilantro or sawtooth herb leaves
• Steamed jasmine rice

Step-by-Step Instructions

Step 1: Soak chiles and prep the tamarind

Place the dried Thai chiles in a bowl and cover with hot water; soak for 10 minutes to soften. If using tamarind pulp, soak 45 g pulp in 1/2 cup (120 ml) warm water for 10 minutes, mash, and strain to yield 3 tbsp (45 ml) tamarind liquid. If using tamarind concentrate, simply measure out 3 tbsp.

Step 2: Make the curry paste

In a mortar and pestle (traditional method) or a small blender, combine the drained chiles, shallots, garlic, grated turmeric (or ground), shrimp paste, and salt. Pound or blend until a smooth, cohesive paste forms, adding 1–2 tbsp of the chile soaking water only if needed to help it blend. A fine paste gives a clearer, more aromatic broth.

Step 3: Prep fish and vegetables

Peel and seed the green papaya (or peel the daikon), then cut into ¾–1 inch chunks. Cut long beans into 2-inch pieces. Cut the fish into 2-inch pieces, pat dry, and lightly season with a pinch of salt. Keep everything ready by the stove.

Step 4: Bloom the paste in the broth

Bring 4 cups (960 ml) water or light fish stock to a simmer over medium heat. Whisk in all of the curry paste until dissolved. Let it simmer for 2 minutes to bloom the aromatics and turmeric—the liquid will tint a deep yellow-orange.

Step 5: Simmer the chunky vegetables

Add the green papaya or daikon and simmer uncovered over medium heat for 10–12 minutes until nearly tender. Add the long beans (and tomato or pineapple, if using) and cook another 3–4 minutes until crisp-tender.

Step 6: Build the hot–sour–salty balance

Stir in 3 tbsp tamarind, 2 tbsp fish sauce, and 1 tsp palm sugar. Taste and adjust: you want bright, forward sourness first, bracing heat, then savory depth with just a whisper of sweetness. Add more fish sauce for salt, more tamarind for tang, and a pinch more sugar only if needed. Optional: add a pinch of white pepper.

Step 7: Poach the fish gently

Lower the heat to maintain a very gentle simmer (about 180–190°F / 82–88°C; no active boil). Slide in the fish pieces and poach for 3–5 minutes, just until opaque and flaking. Overcooking will dry the fish and cloud the broth.

Step 8: Rest, finish, and serve

Turn off the heat and let the curry rest 3 minutes. Taste and make a final adjustment with fish sauce or tamarind. Ladle into warm bowls, garnish with cilantro or sawtooth herb, and serve immediately with steamed jasmine rice and lime wedges.

Pro Tips

• Paste quality matters: a mortar-and-pestle paste releases aromatic oils and gives a cleaner broth than a coarse blender mix.
• Mind the heat: gaeng som is bold. If it’s too fiery, add a splash of hot water and a pinch more palm sugar to round the edges without dulling the sourness.
• Fish choice: center-cut cod, halibut, or snapper hold their shape. Lightly salting the fish 10 minutes ahead helps it stay firm.
• Turmeric stains: use a cutting board you don’t mind tinting and rinse tools promptly.
• Gentle simmer only: boiling breaks the fish and turns the broth murky. Aim for tiny bubbles around the edges.

Variations

• Shrimp gaeng som: swap fish for 1 lb (450 g) peeled shrimp. Add in Step 7 and cook only 2 minutes until just pink.
• Pineapple–papaya: use 1 cup (150 g) pineapple chunks with green papaya for a naturally sweet-sour counterpoint.
• Vegetarian twist: replace shrimp paste with 1 tsp white miso, use soy sauce instead of fish sauce, and add tofu and mushrooms.

Storage & Make-Ahead

The curry is best fresh but will keep 2 days in the refrigerator. Cool quickly and store in an airtight container. Reheat gently over low heat just until hot—avoid boiling to keep the fish tender. The curry paste can be made 3 days ahead (refrigerated) or frozen up to 2 months in a sealed container. Cut vegetables up to 1 day in advance and keep chilled.

Nutrition (per serving)

Approximate: 230 calories; 30 g protein; 6 g fat; 15 g carbohydrates; 2 g fiber; 800–1000 mg sodium (varies with fish sauce). Values are estimates and will vary with ingredient brands and exact amounts.