Heat oven to 375 degrees F. Place potatoes in microwave-safe dish; cover with plastic wrap, venting one corner. Microwave on HIGH 7 to 9 minutes or until just tender; set aside.

Meanwhile, in 3-quart saucepan, heat 2 tablespoons of the butter over medium-low heat until hot. Add apple, onion and celery; cook and stir 5 minutes. Season with 1 teaspoon salt, 1/2 tsp pepper and rosemary. Season inside and outside surfaces of chicken with additional salt and pepper; spoon potato mixture into cavity of chicken. Do not pack. Place remaining stuffing in small casserole dish; sprinkle with 2 tablespoons water and cover with aluminum foil. Close chicken cavity and tie legs together; place on rack in 13 x 9-inch baking pan. Melt the remaining tablespoon butter; brush half the butter on chicken. Roast about 1-1/2 hours or until juices run clear and thermometer inserted into thigh registers about 185 degrees F, basting occasionally with remaining butter and/or pan drippings. Place stuffing casserole in oven during last half-hour of roasting. Remove chicken to platter; let stand 10 minutes before carving. Serve with additional stuffing from casserole.

Recipe Courtesy of The United States Potato Board.