Trim the lamb shoulder and score the skin lightly with a sharp knife. Place it in a roasting dish.
Peel and julienne the carrot. Peel and chop the onion. Peel, degerm, and mince the garlic.
Preheat the oven to 150°C.
Scatter the carrot, onion, and garlic around the lamb. Pour in the white wine and roast for 30 minutes, until reduced. Then add the veal jus.
In a mortar, grind the Sichuan pepper with the Guérande salt and rub over the meat. Mix and apply the remaining spices evenly.
Return to the oven for about 2 hours, basting occasionally. The shoulder will be confit-tender and bursting with flavor.
Serve on a platter with the pan juices in a sauceboat.
