Combine all fish stock ingredients in large pot bring to boil and simmer for 6 hours topping up with water when needed. Strain and reserve. One and half litre stock required for recipe, excess stock can be stored or frozen.
Combine all paste ingredients in food processor. Process until combined scrapping sides if need be.
Peeled prawns, add shells and heads to small pot add enough water to cover bring to boil and simmer for 15 minutes. Strain and reserve.
Add oil to large saucepan and add paste on a medium high heat. Cooked paste for 7 minutes until fragnant.
Add 1.5 litre of fish stock and prawn head stock to saucepan bring to boil. Simmer for 30 minutes.
Add 400ml coconut milk and bring back to boil, simmer again 5 minutes.
Add 3 types of noodles, leave for 1 minute.
Add seafood and bean sprouts take off heat. Leave for 4 minutes, seafood will cook in that time.
Serve and garnish with mix of herbs and nuts.