Step 1

Place the sugar, lime juice and 2 tbs water in a small saucepan over low heat. Cook, stirring, for 3-4 minutes until sugar dissolves.

Step 2

Transfer to a blender with remaining ingredients and whiz until smooth.

Step 3

Transfer to an ice cream machine and churn according to the manufacturer’s instructions. (Alternatively, pour into a shallow container and freeze for 2 hours or until frozen at the edges. Remove from freezer and beat with electric beaters. Return to container and refreeze. Repeat 2 or 3 times.) Transfer to a container and freeze for 4 hours or until firm.

Step 4

Scoop into coconut halves, if using, and scatter with lime zest to serve.