• 660 ml (23 fl oz) peach nectar
• Seeds scraped from 1 vanilla bean
• Juice of 2 limes
• 135 ml (4½ fl oz) sorbet base

Put all the ingredients in a saucepan and heat to 65°C (149°F). Stir until dissolved and then put in the fridge to cool. Transfer to an ice-cream machine and churn until frozen. If you don’t have an ice-cream machine, pour into a shallow freezer container. Freeze until semi-frozen, then whisk very thoroughly. Freeze and whisk again, twice more.