How to cook
Caramelize the sugar in a pot on the stove and carefully pour in red wine. Add the cleaned and dried blueberries and balsamic reduction. Leave the sauce to boil for 6-7 min. Stir the hot prepared sauce with the cold butter.
Heat the oven to 428°F (220 °C) and make slight incisions along the skin of the duck fillet, without cutting down to the meat. Sprinkle with salt and freshly ground black pepper.
Heat a little oil in a nonstick pan (or grill pan) and braise the duck meat for about 5-6 min., with the skin facing down first. Then flip it over and sprinkle with crumbled rosemary, a little more salt and black pepper if needed.
Transfer the braised duck fillets to an aluminum foil sheet and wrap them up like a packet. Put to bake for 7-8 min. in the preheated oven - until reddened.
Make mashed potatoes from the boiled potatoes, stirred and mashed up with the butter and spices. Transfer the duck meat to a suitable plate, cut it into separate thin slices along the skin incisions you made. Add mashed potato garnish and pour on blueberry sauce.