1 cup/225g/7 oz sugar
1 cup/240ml/7¾fl oz water
The juice of one lime
Slice the watermelon in half and scoop out the flesh, removing the seeds as you do so.
Place the sugar and water in a small saucepan and place over a low to medium heat, stirring until the sugar has dissolved.
Remove from the heat and allow to cool to room temperature.
While the syrup is cooling, purée the watermelon in a blender or food processor until the fruit is smooth and strain through a sieve into a bowl.
Stir in the syrup thoroughly and add the juice of the lime.
Serve with plenty of ice – it is a drink that should be served well chilled.