The day before, remove the peel from one carrot and the large onion and dice finely.
Place in a suitable bowl with the pork cheeks, white wine and bouquet garni and marinate for 12 hours.
On the same day, preheat the stove to 150 °C Gard. Drain the pork cheeks, reserving the marinade, season with salt and season with pepper. Heat goose fat in a casserole, fry pork cheeks over high heat until golden brown on all sides (remove from casserole).
Fish the vegetables out of the marinade with a slotted spoon and add to the casserole dish. Roast for 5 minutes, then extinguish with marinade. Add 600 ml of veal stock, bouquet grani and meat. Let it boil once. Put the lid on and put in the stove for 1 hour and a half of cooking.
Meanwhile, remove the peel from the pearl onions. Heat 20 g of butter in a saucepan. Add the onions, season with salt and pepper and add a little sugar. Toss briefly, then just cover with water. Simmer uncovered on a gentle fire for 25-half hours. Remove the skin from the remaining carrots, cut them into small pieces and cook them in the same way as the onions in another saucepan.
10 minutes before the meat is ready, add the chestnuts to the casserole dish and put it back on the stove.
Put the pork cheeks on a plate, pour the sauce over them and add the carrots, chestnuts and onions.