Watermelon, rose and lime sorbet

Method

• 1
  Combine sugar and 500ml (2 cups) water in a saucepan and cook, stirring, over low heat for 5 minutes or until sugar dissolves. Refrigerate for 30 minutes or until cool.
• 2
  Meanwhile, place watermelon, rosewater and lime juice in a blender and blend until smooth. Strain through a sieve, pressing with the back of a spoon to extract as much liquid as possible (you’ll need 600ml watermelon juice). Combine watermelon juice and cooled sugar mixture.
• 3
  Pour into a 1.5L (6-cup) container and freeze for at least 2 hours or until almost set.
• 4
  Roughly break up sorbet and transfer to a food processor. Process until sorbet is smooth and has a soft, icy texture. Return to container and freeze for at least 2 hours or until firm. Repeat processing and freezing twice more.
• 5
  Return sorbet to food processor with egg whites and zest, then process until pale and smooth.
• 6
  Spoon sorbet into container, smooth surface with the back of a spoon, then scatter with dried rose petals. Freeze for at least 2 hours or until firm.