Cook sushi rice following packet directions and allow to cool. Press a quarter of the rice over a nori sheet.
Combine mayonnaise, lime rind, juice and coconut and spread a little over the rice. Place some lettuce down the centre of the rice, top with John West Tuna and slices of mango.
Roll up tightly and wrap in plastic wrap. Repeat to make 4 rolls. Chill until ready to serve. Remove plastic and cut into slices, serve with pickled ginger.