1. Put litchi flesh and sugar in a blender or food processor and process to a puree.
2. Press the puree through a fine strainer to remove any remaining solids.
3. Transfer to a freezer proof container and freeze for 3 hours.
4. Turn the mixture into the blender or processor and process until slushy.
5. With the motor running add the egg white.
6. Return mixture to freezer proof container and freeze for 8 hours/over night.
7. Puree sorbet in blender right before serving, garnish with thinly sliced lemon.