1½ cups caster sugar
1 cup basil leaves, firmly packed
2.5kg seedless watermelon
1 tbsp white rum
2 tbsp finely chopped basil leaves
½ cup white rum, extra
1.5 litres pink moscato or lemonade, chilled small basil leaves, to serve
Combine sugar and 1½ cups water in a medium pan over medium heat. Bring to the boil, stirring to dissolve sugar. Simmer for 1 minute. Add basil; remove from heat. Cover and set aside to cool. Strain syrup and refrigerate until cold.
Remove watermelon rind and roughly chop 1.5kg flesh. Process until smooth. Push puree through a sieve. You will need 3 cups watermelon juice. Finely chop remaining watermelon for serving.
Combine sugar syrup, watermelon juice and 1 tbsp white rum in a large jug. Transfer to an ice-cream machine and freeze according to instructions, adding chopped basil in the last 10 minutes of churning. Transfer to a container and freeze for 4 hours or until firm.
To serve, take 6 tall glasses. Place 1 tablespoon white rum in each glass. Top each with 2 scoops of sorbet and a spoonful chopped watermelon. Top up with moscato/lemonade. Sprinkle with small basil leaves to serve.