Drain the apricots well on a sieve. Collect the fruit juice. Mix 3 tablespoons of juice and cornstarch. Bring the fruit juice, apricot nectar and vanilla sugar to the boil, stir in the starch and bring to the boil again.
Cut the apricot halves into slices and fold into the thickened juice. Let the compote cool completely, arrange on plates. Cut the ice cream into slices and place on the compote. Decorate as desired with cocktail cherries and lemon balm.
Serve immediately.