This is stunning: refreshing, slightly tart and such an inspiring colour to bring out of your kitchen. Sometimes I like to serve it with a shot of vodka or a gentle blob of whipped cream alongside. You could also add a little liqueur to the sorbet if you like. Unfortunately, this doesn’t work too well without an ice-cream machine — you can beat it by hand, but you will end up with a sort of granita instead of a sorbet.