550g seedless watermelon, skin removed and chopped
200g canned lychee, well drained (reserve the syrup)
¼ cup lychee syrup
1 egg white
To prepare sugar syrup
Combine water and sugar in a saucepan. Cook to a simmering boil over medium-low heat until sugar dissolves completely.
Gradually increase the heat and bring to a quick boil again. Reduce the heat and cook for 5 minutes or until the syrup thickens.
Set aside to cook completely.
Blend watermelon and lychee in a food processor, in several batches, until smooth. Strain the watermelon and lychee puree.
Stir sugar syrup and lychee syrup into watermelon and lychee mixture. Mix until well combined. Pour into an airtight container, cover and freeze for 4-5 hours or until almost set.
Remove sorbet from the freezer and mash with a fork, then transfer to a food processor and process until mixture is smooth and has a soft, icy texture.
Refreeze the mixture in a covered container for 3-4 hours until it is firm. Remove from freezer and break up sorbet again and process in a food processor again.
Return to plastic container and refreeze for several hours until firm. Place sorbet and egg white in a food processor and blend until sorbet is pale and smooth. Return to the container and refreeze for 4-5 hours until almost firm. Scoop with an ice-cream scoop into serving glass bowls and serve immediately.