Bring milk, fat and 1 teaspoon of sugar to the boil. Add semolina while stirring until the mixture comes off the bottom of the pot as a lump. Remove from the heat, let it cool down a bit and stir in the egg.
Form small dumplings from it. Put them into boiling water and let them simmer at low heat for about 10 minutes. In the meantime, wash and quarter the apples and cut out the core. Cut quarters into thin slices.
Heat lemon juice. Briefly braise apple slices in it. Add lilac berry juice, apple juice, remaining sugar and cinnamon stick, bring to the boil. Stir cornflour and 2 tablespoons of water into the soup until smooth and bring to the boil again.
Add semolina dumplings to the soup and heat up. Garnish the soup with lemon spiral and mint leaves to taste. Serve hot or cold as desired.