Mussels in spiced coconut broth

Name: Mussels in spiced coconut broth
Ingredients: 1 kilogram medium black mussels, scrubbed, beards removed; 1 cup (250ml) water; 3 cup (750ml) fish stock; 10 centimetre (50g) piece fresh ginger, thinly sliced; 2 fresh small red thai chillies, thinly sliced; 4 clove garlic, thinly sliced; 3 dried curry leaves; 4 (100g) shallots, thinly sliced; 1 tablespoon fish sauce; 1 teaspoon finely grated lemon rind; 2 teaspoon lemon juice; 1/2 cup (125ml) coconut milk; 1 cup firmly packed fresh coriander leaves