The hami melon is large and oval, with pale orange, sweet, perfumed flesh. If you like, substitute cantaloupe or honeydew for the hami melon. If you're feeling really indulgent, use a Japanese crown melon. Whichever melon you choose, make sure it's ripe, and therefore, sweet. Start making the sorbet that accompanies it first because you need to allow time to make the syrup and let it and the lemon and lime juices chill before processing in the ice-cream machine. Once churned, it needs time to...