An enticing Christmas classic with an exotic twist.
Starting from the neck of the guinea fowl, gently detach the skin from the flesh and slide the truffle slices under it, distributing them evenly. Leave the guinea fowl to rest in a casserole dish with the lid on, in the refrigerator until the next day, to allow it to take on the flavor of the truffle.
Preheat the oven to 180 °C (convection). Cook the guinea fowl for 1 hour and 15 minutes to 1 hour and 30 minutes. Meanwhile, peel and rinse the potatoes, and cut them into large cubes. Immerse the potatoes and coarse salt in a saucepan filled with boiling water. Allow them to cook for around 30 minutes until soft.
Split the vanilla pod in two, lengthwise and scrape the inside with the tip of a knife to remove the seeds. Add the rest of the cold butter and mix again. Season with salt. When the puree is nice and fluffy, arrange it in a dish.
Pour the milk, a quarter of the butter cut into cubes, and the vanilla seeds into another saucepan on a medium heat. Pass the potatoes through a food mill over this saucepan and stir vigorously. Serve with the truffle flavored guinea fowl.