Gaeng Som (Thai Sour Orange Curry)

Gaeng Som is a fiery, tangy curry born in the central and southern regions of Thailand, where tamarind-laced broths and fresh river fish have fed families for centuries. Unlike coconut milk-based curries, this austere, intensely flavored dish relies on a pounded paste of dried chilies and shrimp paste to deliver a bold, sour heat that wakes up every taste bud.

Ingredients

500g firm white fish fillets (snapper or catfish), cut into 5cm chunks

200g green papaya, peeled and cut into matchsticks

100g yard-long beans, cut into 4cm pieces

4 cups (1 liter) water or light fish stock

3 tablespoons tamarind paste (from a block, dissolved in warm water and strained)

2 tablespoons fish sauce

1 teaspoon palm sugar

8 dried Thai red chilies, soaked in warm water for 15 minutes and drained

4 fresh red bird's eye chilies

1 tablespoon shrimp paste (kapi)

5 shallots, roughly chopped

1 tablespoon galangal, roughly chopped

1 teaspoon turmeric powder

1 stalk lemongrass, white part only, sliced

1 teaspoon salt

Instructions

Make the curry paste: In a mortar and pestle, pound the soaked dried chilies, fresh bird's eye chilies, shallots, galangal, and lemongrass together until a rough paste forms, about 5 minutes of steady pounding. Add the shrimp paste, turmeric powder, and salt, and continue pounding until the mixture becomes a smooth, unified paste with no large chunks remaining.

In a medium saucepan, bring the water or fish stock to a boil over medium-high heat. Add the entire curry paste and stir vigorously to fully dissolve it into the liquid, cooking for 3 minutes until fragrant.

Add the tamarind paste, fish sauce, and palm sugar to the pot. Stir to combine and taste the broth — it should be sharply sour, moderately salty, and have a background heat. Adjust with more tamarind for sourness, fish sauce for saltiness, or palm sugar to balance, adding each in small increments.

Add the green papaya matchsticks and yard-long beans to the boiling broth. Cook for 5 minutes until the vegetables are just beginning to soften but still have some bite.

Gently lower the fish chunks into the simmering curry. Cook for 5 to 7 minutes without stirring aggressively, until the fish is opaque and cooked through, and flakes easily when tested with a fork.

Remove the pot from heat immediately once the fish is cooked to prevent overcooking. Taste one final time and adjust seasoning if needed. Ladle the Gaeng Som into deep bowls and serve immediately alongside steamed jasmine rice.