Orange Sauce for Duck

Duckling à l’orange is another French classic, not to mention one of the first dishes I learned to make at the La Varenne cooking school in Paris. The sauce owes its unique sweet-sour-caramel flavor to a mixture of burnt sugar and vinegar called a bigarade. The traditional preparation calls for oranges, but I also like the exotic flavor you get with tangerines. To reinforce the orange flavor, place a few strips of the orange zest in the cavity of the duck before grilling.