Take a square of baking parchment 30cmx 30cm. Place a handful of mussels in the centre. Add a lime leaf, lemongrass, chili, coriander and basil leaves.
Take one corner and fold in half to meet the opposite corner. Tightly fold the paper all along the edge to form a half moon. Just before it is completely sealed, form a spout with the open end and pour in a little coconut milk and a splash of fish sauce.
Seal and place on the BBQ for ten minutes. Open with a pair of scissors, squeeze over the lime and serve.