- Preheat the oven to 200 °C
- Insert the rosemary branch inside the guinea fowl after removing the excess fat. Put the guinea fowl in a dish, add salt and pepper on both sides and brush with olive oil.
- Peel the onion, slice it finely and place it around the guinea fowl. Cook in the oven for 90 minutes.
- After a few minutes’ cooking, add 50cl of boiling water. Wet the guinea fowl from time to time while it’s cooking.
- When it is cooked, take the guinea fowl out of the oven and keep it warm.
- Take out about half a bowl worth of sauce and keep it aside.
- Deglaze what is left in the dish with some calvados, add some sugar and sprinkle with ground nutmeg.
- Peel and slice the apples. Place them in a dish and cook at 240 °C until they are golden.
- Reheat the chestnuts in the half-bowl of sauce you had kept aside.
Serve the guinea fowl with the apples, some sauce and some chestnuts. Serve hot.