zest one orange; set aside. peel another orange seperate orange sections; set aside. Insert the garlic and orange sections in duck cavity. rub the skin with salt and pepper according to your liking. Place on a rack in a roasting pan. Roast in a preheated oven at 350 degrees f, occasionally brushing the duck with 1/2 cup orange juice and pricking the skin with a meat fork, for 1 hour, 10 minutes. increase the oven temperature to 475 f and continue roasting till skin is crisp and the juices run pink when the duck is pierced with fork, about 20 min to 25 minutes more. transfer the duck to serving platter.
Skim the excess fat from the roasting pan. Add the rest 1/2 cuporange juice, zest, and the orange liqueur. cook the orange juice mixture over high heat, scraping the the browned residue up with a wooden spatula, until it is reduced by half. remove from heat and mix in butter. season with salt an pepper to taste. cut your duck up in quarters with poultry shears. serve with orange sections and sauce.