- With the rack in the middle position, preheat the oven to 190 °C (375 °F).
- With a sharp knife, score skin and fat of each duck breast without cutting meat.
- In an ovenproof non-stick skillet, brown duck breasts, fat side down, for about 15 minutes over low heat. Season with salt and pepper. Remove any excess fat from the skillet and set 15 ml (1 tablespoon) aside. Turn duck magrets over and bake for about 8 to10 minutes for medium doneness. Place breasts on a plate and cover with aluminum foil. Let rest for 5 minutes. Discard remaining fat.
- In the same skillet, brown sugar with vinegar. Deglaze with broth and juice. Bring to a boil and reduce over high heat until syrupy. Add oranges and cook just to warm segments. Off the heat, add butter and agitate the skillet until sauce is smooth. Do not stir sauce with a spoon to avoid breaking orange pieces. Adjust seasoning.
- Slice meat and drizzle with sauce.
- Serve with baby potatoes or mashed potatoes and celeriac.