To start the sauce, zest and juice the orange

In a pan, heat the sugar with the red wine vinegar. Allow to reduce until a dark syrup is left.

Add the chicken stock and orange juice. Bring to the boil and simmer to reduce until desired consistency. Alternatively, stir in 1 tsp of cornflour paste and allow to simmer for 2 minutes.

To finish add the orange zest and season with salt and pepper. Serve with duck breast or whole roast duck.