For the coconut fish curry with pumpkin, first prepare the pastes. For the lemongrass paste, slice the lemongrass. Peel and finely chop the galangal, fingerroot and turmeric. Cut lime leaves into fine strips. Cut garlic in half. Grate the zest of the lime. Grind all ingredients into a paste with a mortar.
For the chili paste, seed the chili peppers. Place in the slightly warmed water for about 5 minutes. Then squeeze out the water. Use a mortar or cutter to make a paste. Sauté in the oil until the paste is fragrant and then let cool.
Debone the fish, if desired, and cut into finger-width strips. Peel the pumpkin, if necessary, depending on the variety, cut into finger-width strips and blanch.
Heat half of the coconut milk and reduce by half. Add fish sauce, 2 tbsp of the fish paste and 8 tbsp of the lemongrass paste and the shrimp paste and simmer until fragrant. Then add the fish and squash. Pour in fish stock and season well with the spices. Simmer for a few minutes. Remove the fish and pumpkin, then puree the sauce. Top up with the remaining coconut milk and simmer again briefly. Add the pumpkin and fish back in. Serve coconut fish curry with pumpkin.