Watermelon and Vodka Granita with Lime and Ginger Syrup

Woo hoo! Fruit and booze slushy with a sweet sticky syrup? What's not to love?! This is an absolute winner...   Ingredients 1 small watermelon, peeled and deseeded 130ml vodka For the syrup 150g caster sugar Zest and juice of 2 limes 40g fresh ginger, grated A few fresh mint leaves, chopped   To prepare…