Water - 300 ml
Caster sugar - 200 g
Unwaxed lemons - 4
Egg white - 1
1) Heat the water and sugar in a saucepan, stirring occasionally, until the sugar has dissolved.
2) Pare the rind of two of the lemons into the pan and then simmer for another 2 minutes. Leave to cool and then refrigerate for 15 minutes.
3) Stir in the juice of all 4 lemons and then strain (to remove the rind) into a shallow freezable container and freeze for 4 hours.
4) Remove from the freezer and mash with a fork to break up the ice crystals. Whisk the egg white until frothy and then stir it into the sorbet. Freeze again for at least 4 hours before serving. Serves 4-6.
To make lime sorbet, replace the lemons with the rind of 3 and juice of 6 limes.