Preheat oven to 150°C. On the stove top, heat olive oil in a large, ovenproof casserole dish.
Season the duck skin with Bavarian Roast Chicken Spice, then place into the pan skin side down. Cook until the skin is golden brown, then turn and quickly sear the flesh side. Remove from pan and set aside.
Pour off most of the duck fat from the pan (keep the fat and use it for roast potatoes at a later date!). Add the chopped onion, carrot, celery, whole garlic cloves and cook, stirring until softened. Add the baby onions and button mushrooms and cook until they have taken on a little colour, then add the spices and cook for about 5 minutes.
Return the duck to the pan and pour in the wine. Simmer until it has reduced a little, then add the stock. Bring to the boil, cover and place in the oven. Cook for 1 ½ – 2 hours, or until the duck is very tender and falling off the bone.
Meanwhile, combine milk with 500ml of water and bring to the boil over medium heat. Gradually add the polenta to the liquid, whisking continuously, then whisk (and then stir) until thick and silky – about 10 minutes. Stir through the butter and parmesan and season to taste.
Once duck is tender, remove the duck, mushrooms, garlic cloves and baby onion from the liquid, then return the pan to high heat and reduce cooking liquid by about half. Return the duck and vegetables to the pan to warm through and glaze.
