Ingredients:

2 pounds fish bones,using head and tail parts
10 cups water
15 spring onions, pounded
15 shallots,divide into 5 and 10 pieces
15 cilantro roots, divide into 5 and 10 pieces
1 teaspoon roasted shrimp paste
3 tablespoons palm sugar
¼ cup tamarind water
1 tablespoon lime juice
½ teaspoon salt
1 tablespoon ground white pepper
1 tablespoon ginger, julienne
1 tablespoon spring onions,sliced,white part only
3 ounces black cod fillet,sliced into 6 small pieces

Methods:

Simmer fish bones on low heat with pounded spring onion, 5 shallots and 5 cilantro roots in water for 1 hour. Do not boil or the stock will become cloudy. Occasionally skim off scum. Discard the fish bones. Blend roasted shrimp paste, remaining shallots, remaining cilantro roots and 1 cup of the stock and stir. Season the broth with palm sugar, tamarind water, lime juice and salt. Leave to simmer until the soup turns light brown. Strain through a cheese cloth or very fine sieve. Leave to settle and use only the clear portion . Discard the sediment. Extra broth can be frozen for later use.

To serve, boil each serving of the soup in a pot. Add the ginger, spring onions and cod. Season with salt and pepper to taste. Serve as soon as the cod is just cooked.