Remove the green leaves from the strawberries and blend the berries with icing sugar, lemon juice and water until smooth. Place in the freezer overnight.
Soak the gelatine in water as cold as possible for 10 minutes. Pour the cream into a saucepan. Scrape the seeds out of the vanilla pod and add them to the cream along with the split vanilla pod.
Add the sugar and let it simmer gently for approx. 5–10 minutes. Remove the saucepan from the heat once it has reached boiling point and remove the vanilla pod. Pour the cream into a bowl, squeeze out the excess water from the gelatine and add it to the cream, stirring until dissolved.
Pour the cream through a sieve into 4 serving bowls and place them in the fridge for at least 3 hours, until the cream has set to a velvety consistency.
Chill four shallow bowls in the fridge for at least 30 minutes. Cut the strawberries into quarters and toss them with sugar. Leave them to stand for about 10 minutes.
Warm the bowls containing the custard in a little hot water and turn them out onto the plates. Arrange the strawberries around the custard.
Remove the granita from the freezer, scrape off flakes with a fork and place them over the custard. Finally, sprinkle with a little orange zest and, if desired, finely chopped basil.
