Plumped dried currants and toasted pecans give this spicy preserve a nutty sweetness and a chunky thickness. While it makes a sumptuous accompaniment to duck, it also pairs beautifully with venison, pork, and chicken.
Stem and slip skins off grapes; reserve skins for later use. In a medium saucepan over low heat, cook grape pulp until softened, about 5 minutes. Place a fine-mesh sieve over a bowl and pour in grape mixture. Press pulp with the back of a spoon to separate seeds from pulp; discard seeds.
Transfer pulp back to saucepan. Add reserved grape skins, dried currants, maple syrup, port, brown sugar, vinegar, and cloves. Bring mixture to a boil, reduce heat to medium, and simmer 15 minutes; stir occasionally as mixture thickens. Let cool slightly and then stir in pecans. (You may make this conserve recipe a week ahead; just cool, cover, and refrigerate. Bring to room temperature before serving.)
Season duck breast halves on both sides with salt and pepper and set aside. Heat a large skillet over medium setting 2 minutes; skillet will be very hot. Add duck breasts skin side down and cook 12 to 15 minutes, until skin is crisp and excess fat is released. Turn duck and cook 3 minutes longer for medium doneness (still pink in the center).
Remove duck from skillet and let rest 5 minutes on a cutting board. Carve breasts on the diagonal into thin slices. Arrange duck on plates and top with any juices that have accumulated on cutting board. Serve with maple-grape conserve on the side.