Wash, stalk and stone the cherries. Set 2 cherries aside. Halve the rest of the cherries if necessary. Boil up the cherry nectar. Add cherries and sugar, bring to the boil.
Stir groats powder with 3-4 tablespoons of water until smooth, thicken cherry nectar with it, bring to the boil again and simmer for 1-2 minutes. Pour into glasses and let cool off. Mix quark, cream and vanilla sugar. Spread the quark cream over the groats. Decorate with cherry quarters and pistachios
With 8 people: