Cut the onion into wedges and place it in a pan with some clementine cut into wedges, leaving the peel (obviously they must be well washed).
Cook at 220 ° C for 2 hours. If you notice that the top of the capon gets too brown, place some silver paper on top and let it cook.
Halfway through cooking, after 1 hour, deglaze with the wine. Return to the oven and occasionally sprinkle the capon with the cooking juices, to ensure that it remains moist and soft.
Serve hot, fresh from the oven!
By @Frollemente