Boil up the lilac berry and apple juice. Peel apples, quarter them, remove the core. Cut apple quarters into thin slices and add them to the boiling fruit juice with the cinnamon and star anise. Cook for about 3 minutes. Add lemon juice and sugar.
Stir cornflour and some cold water until smooth. Thicken the juice with it, bring to the boil again and possibly add some sugar to taste. Serve the lilac berry soup on plates. Garnish with mint leaves as desired