Clean, wash and roughly grate the carrots. Sprinkle with half of the lemon juice. Wash the apples. Cut out about 1/4 of the apple, remove the core. Cut the fruit flesh into slices.
Peel the rest of the apples, quarter them and cut out the core. Grate apple roughly and sprinkle with remaining lemon juice. Divide muesli, grated carrots and apples into four bowls and pour on lemon butter milk. Serve with apple slices and decorated with mint to taste. Serve immediately