1. Remove giblets and neck from duckling. Remove and discard excess fat from inside body cavity. Cut off and discard excess neck skin. Rinse duckling, giblets, and neck in cold water and pat dry with paper towels. Cut off and reserve first 2 joints of the wings, leaving only the third. To cut duckling into quarters, using poultry shears, cut duckling lengthwise in half through the breastbone and continue cutting along one side of the backbone; cut duckling halves in half crosswise.
2. Coat bottom of 5-quart kettle or Dutch oven with nonstick vegetable cooking spray. Add giblets, neck, and reserved wing tips to kettle and cook until well browned. Add duckling quarters, water, onion, carrot, 1/2 teaspoon salt, and the bay leaf. Cover and heat to boiling over high heat. Reduce heat to low and simmer, covered, until duckling is fork-tender about 1 hour. (If preparing ahead, remove duckling from kettle, cool, wrap, and refrigerate. Strain cooking liquid, discarding fat and cooked particles. Refrigerate liquid, or duck stock.)
3. Just before roasting duckling, prepare pomegranate glaze: In 1-quart saucepan, heat jelly until melted. Stir in pomegranate juice and sugar and heat to boiling over high heat. Boil mixture 5 minutes; remove from heat and set aside.
4. Heat oven to 450 degrees F. Remove duckling from kettle and place, skin side up, on rack in roasting pan. (If duck breasts have curled up after boiling, remove their breast bones so they will be flat.) Roast duckling 15 minutes.
5. Meanwhile, pour duck stock through large strainer into bowl, discarding cooked particles. Remove excess fat from stock. Reserve 1 cup stock for the sauce and 2 cups stock for Dried-Fruit Couscous; refrigerate remainder for another use.
6. Brush duckling with some glaze and roast 5 minutes; roast duckling 10 more minutes or until well browned, brushing 3 more times with glaze. Prepare Dried-Fruit Couscous; keep warm. Set duckling quarters aside.
7. Prepare sauce: In cup, combine wine and cornstarch until smooth. Stir reserved 1 cup stock and remaining 1/4 teaspoon salt into glaze remaining in saucepan. Heat to boiling and stir in cornstarch mixture. Cook, stirring constantly, until thickened. Pour sauce into serving bowl.
8. Spoon Dried-Fruit Couscous onto serving plate. Arrange duckling on couscous. Garnish with mint, if desired. Serve duckling and couscous with sauce.