Preheat oven to 350 F. Rinse chicken and pat dry. In a large bowl, toss stuffing with water. In larger skillet, melt margarine over medium heat. Add onion, spinach, ham, garlic, sage and rosemary to skillet; saute until tender, about 5 minutes. Add spinach mixture to stuffing. Stir in heavy cream and lemon juice; mix well.
Spoon stuffing mixture into chicken cavity. Fold skin over openings and close with metal skewers. Tuck wings under chicken. Place on roasting rack in a roasting pan.
Roast until thigh temperature reaches 180 F. and chicken is golden, about 2 hours.