In a soup pan heat the fish stock, lemon rind, galangal, chilli, and shallots, and bring to the boil for 4 -5 minutes.
Add the prawns, mushrooms, tomatoes, and cook for a further 3 - 4 minutes until the prawns are cooked.
Remove the pan from the heat and add the tamari, lime and apple concentrate.
Note: The RDI of sodium is 920 - 2300mg. Sodium is found in food naturally and accounts for approximately 800mg of that daily recommended intake. Many Asian sauces and pre prepared meals are particularly high in sodium so try and select sodium reduced alternatives where possible.