Peel the mango and cut it into slices from the stone. Put some slices aside for garnishing, mash the rest. Stir mascarpone, quark, lemon juice and zest, vanilla sugar and sugar until smooth.
Put the mango puree into a glass bowl. Fill with mascarpone cream and smooth it down. Warm up the jelly a little and put it into a freezer bag. Cut off a small corner. Decorate the cream with small dots and pull through with a wooden skewer from top to bottom.
Decorate with mango wedges and lemon balm.