Thai Green Curry Mussels

Name: Thai Green Curry Mussels
Yield: Makes 4 Servings
Cuisine: Thailand
Ingredients: Kaffir lime leaf, 1 (optional); Lemongrass, 1 stalk; Thai green curry paste, 1 tablespoon; Unsweetened coconut milk, 1 can (14 fl oz/430 ml); Fresh basil or mint, 3 tablespoons slivered; Asian fish sauce, 1 tablespoon; Mussels, 1½ lb (750 g), scrubbed and debearded if necessary