Coarsely chop the chocolate coating and melt in a water bath. In the meantime, cut the vanilla pod lengthwise and scrape out the vanilla pulp. Let the chocolate coating cool down a little. Mix quark, crème fraîche, cream, vanilla pulp, sugar and lemon juice with the whisk of the hand mixer.
Pour vanilla curd into a piping bag with a large perforated spout and squirt into four dessert glasses. Put the couverture into a small freezer bag, cut off one corner with sharp scissors and spread the couverture spirally over the vanilla-Q
Serve as desired, decorated with mint and nibbles.