Preheat oven to 350 degrees F (175 degrees C). Grease a baking dish. Pour out half the beer from the can, spray the can with cooking spray, and set it upright in the center of the baking sheet.
Cut 2 thin slices from the orange, and set aside. Cut the rest of the orange into large chunks. Loosen the skin over the breast of the chicken, and insert an orange slice, an onion slice, and 1 rosemary sprig under the skin of each side of the breast. Place the orange chunks and 2 sprigs of rosemary into the cavity of the chicken.
Spray the outside of the chicken with cooking oil spray, and sprinkle with seasoned salt to taste. Place the chicken onto the beer can in an upright position, with the can inserted into the cavity of the chicken. Pour the chicken broth into the baking dish, and place the rest of the sliced onion and the potatoes into the broth.
Roast in the preheated oven until the skin is crisp, the meat is no longer pink at the bone, and the juices run clear, about 1 1/2 hours. An instant-read thermometer inserted into the thickest part of the thigh, near the bone should read 180 degrees F (82 degrees C). Let the chicken rest for 10 minutes before slicing.