1/3 cup caster sugar
finely grated zest 3 lemons
½ cup lemon juice
½ cup water
1 cup soda water
softly whipped cream
zest of 1 lemon
Place the sugar, lemon zest and juice and the water in a small saucepan. Heat, stirring until the sugar dissolves, then simmer gently for two minutes.
Stir in the soda water then pour into a shallow freezer-proof container. Freeze until just starting to set around the edges.
Stir the mixture with a fork, breaking up any large chunks, dragging the frozen ice from the sides into the centre. Repeat twice more until no large pieces of ice remain. Cover tightly with plastic wrap once frozen.
To serve: Scoop the granita into serving glasses and top with whipped cream and lemon zest.