Clean, wash and thinly slice the strawberries, except for six strawberries for decoration. Clean and wash the rhubarb and cut it into thin diagonal strips. Bring 1/4 litre water and sugar to the boil.
Add the rhubarb and steam for one minute. Drain the rhubarb and let it drain. Peel off the chocolate with the peeler. Mix lemon juice, orange liqueur and vanilla sugar.
Sprinkle strawberries and rhubarb with it. Arrange the fruit on plates and decorate with lemon balm and the rest of the strawberries as desired.