This is so basic that it is almost not a recipe at all.
You only need a leg of such per person and around 100 gr of diced butternut squash and sweet potato per person (some supermarkets sell them already diced), a bit of olive oil (2-3- tablespoons) and salt.
Preheat the oven at 250 degrees. Salt the duck. Put the duck on a tray with a bit of water. Roast 20 minutes at 250 degrees. Then add the olive oil and salt to the vegetables and add it to the duck. Roast for a further 10 minutes. Lower the temperature to 200 degrees and roast for another 30 minutes. It is a very nice and simple dinner.