sentence: add lime rind chili kaffir lime leaves and lemon grass to chicken stock and stir sentence: when it boils cover and simmer gently for twenty minutes sentence: strain the soup into a bowl and pour into a pan sentence: add the fish sauce lime juice salt and pepper sentence: put the soup on the stove and bring to a boil sentence: when the soup is boiling add prawns and simmer gently for two minutes sentence: garnish with red chili spring onion and coriander