Bring the orange juice to the boil with the sugar. Stir the starch in a little cold water until smooth, mix into the orange juice and bring to the boil briefly. Add the berries, stir and let cool.
Mix the mascarpone, quark, sugar, lemon juice, espresso and vanilla flavor together. First put 2 tablespoons of berry compote in four glasses, then 2 tablespoons of mascarpone cream, then again berry compote, etc. Garnish with whipped cream and sprinkle with chopped pistachio nuts.