Make this Berry Granita or choose another frozen dessert from the online selection at waitrose.com/recipes
Place 300ml water in a pan with 150g granulated sugar, and the zest and juice from a lime. Heat gently until all the sugar has dissolved. Boil for 3 minutes, then remove from the heat and allow to cool. Liquidise 500g strawberries or raspberries with the syrup until smooth, sieve to remove the pips, and pour into a shallow plastic container.
Freeze for 2 hours, or until the mixture is frozen around the edges.
With a fork, draw ice from the edges towards the centre. Return to the freezer, and then repeat this process about 3-4 times, every 30 minutes, or until all of the granita mixture is formed of ice crystals.