Preheat oven to 425. Place the chicken in a roasting pan.
In a small bowl, mix together the sage, garlic, butter, and salt. Using your hands, spread the sage butter all over the outside of the chicken.
Roast the chicken for 75-85 minutes, or until browned and crisp on the exterior and juices run clear. Rest chicken 10-15 minutes.
Meanwhile, to a small saucepan add the pomegranate juice and pepper. Bring to a boil, reduce heat to medium-low, and simmer until reduced to a thick syrup that coats the back of a spoon, about 15 minutes. Drizzle half of the glaze over the whole chicken, reserving the rest for serving.
Slice the chicken as desired, drizzle with more glaze (if the sauce has firmed up, just put it back on the heat for 30 seconds or so), and sprinkle with pomegranate seeds (optional). Serve.
Adapted from In Sock Monkey Slippers.