Rinse and dry the duck.
Season well with salt and pepper. Coat with vegetable oil. Put on a baking sheet covered with parchment.
Cut oranges into quarters.
Place oranges inside the duck. Sew up or hammer with toothpicks.
Cook the duck in a highly preheated oven at 220-250 degrees C for 30 minutes. Reduce temperature to 180 degrees and cook for another 2 hours. Periodically pouring fat from a baking sheet. Cut the quince into circles and 20 minutes before the end of cooking, put on a baking sheet next to the duck.
Divide the finished duck into pieces and serve with orange and quince slices.
Bon appetit! Happy New Year!