For the compote, cut the vanilla pod lengthwise and scrape out the pulp. Wash the quinces and rub dry. Quarter the fruits, peel them and cut out the core. Dice 2 quinces. Boil up with apple juice, 75 g sugar, vanilla pulp and vanilla pod.
Simmer covered at low heat for about 45 minutes.
Cut the remaining quince into slices and add to the compote after 20 minutes. As soon as the compote (not the slices) is mushy, stir the starch and 2 tablespoons of water until smooth and add to the compote. Bring to the boil and simmer for about 1 minute.
Let it cool down.
Heat the cream and 25 g of chocolate in a small pot while stirring until the chocolate has melted. Allow to cool slightly and fill into a disposable piping bag or freezer bag. Cut off a very small tip and decorate the dessert plates with it in stripes.
Peel 50 g of chocolate with a peeler and remove fine rolls. Form 4 small balls from the ice cream and let them thaw very briefly. Roll them in the chocolate rolls, cover them and put them back in the freezer for about 30 minutes.
Remove the vanilla pod from the compote. Arrange the compote and ice cream on the dessert plates.