Warm the orange juice in a sauce pan over a medium heat

Remove from the heat and leave to cool

Cut your watermelon into chunks, removing the peel, and juice

Pass through a sieve to get your 800 grams

Add the watermelon juice and lemon juice to the orange syrup

Mix well and pour into a lidded container that can go into the freezer

Remove every hour and whisk - do this until the ice crystals begin to form

Leave to freeze completely before scraping off the granita with a fork, to serve

Best used within the first 3 days of maming