Put about 400 ml water and lemon juice in a bowl. Wash quinces thoroughly, peel, quarter and cut out the core. Cut the quinces into fine cubes and put them immediately in lemon water
Onions peel and chop finely. Peel and finely chop the ginger. Pour quinces into a sieve and drain. Heat the oil in a wide saucepan and sauté the onions and ginger. Add the quinces and fry briefly. Dust with sugar and let it caramelize slightly while turning. Deglaze with vinegar and apple juice, bring to the boil. Let it boil down at low to medium heat for about 40 minutes. Then season with salt and pepper.
Remove from the heat, pour into a bowl and allow to cool. Cheese tastes good with it