For five generations, Louis Roque has been distilling the abundant walnuts of the Dordogne into an addictive elixir called La Vieille Noix. The fine liqueur, tart raspberries, and walnuts marry for a beautiful and elegant pan sauce for seared duck breast.

Makes 4 servings

2 duck breasts, preferably magret (1/3 to 1/2 lb/155 to 250 g each)
Coarse salt and cracked pepper
2 tablespoons (30 ml) Armagnac
2 tablespoons (30 ml) walnut liqueur, preferably La Vieille Noix
2 tablespoons (30 ml) demi-glace
1 cup (125 g) fresh raspberries
1/2 cup (60 g) walnut halves, toasted

With a sharp knife, trim any excess fat from the edge of each duck breast. Score the fat on the top of each breast at 2-inch (5-cm) intervals in a crisscross pattern, being careful not to cut into the flesh. Season with salt and pepper.

Place the duck breasts, skin side down, in a heavy frying pan over medium heat. Cook, uncovered, until the skin begins to brown, 5 to 8 minutes. Reduce the heat and continue to cook until the skin is brown and begins to crisp, about 5 minutes longer. Turn the breasts over and cook until crisp, 3 to 4 minutes longer. Transfer the duck breasts to a plate and pour off all but 1 tablespoon of the duck fat from the frying pan.

Return the pan to medium heat and add the Armagnac and walnut liqueur; be careful as the pan may flame up. Deglaze the pan, using a spatula to loosen any browned bits from the bottom. Add the demi-glace and raspberries and cook for 30 seconds. Add the walnuts and stir until heated through, about 30 seconds. Do not overcook the sauce; the raspberries should hold their shape.

Starting at the smaller end, thinly slice the duck breast at a 45-degree angle. Arrange the slices on four serving plates and spoon the sauce on top.