Preheat oven to 400 degrees. Place chicken into roasting pan.
Mix together lemon juice, salt, pepper, oil and rosemary, Apply rub under skin on meat and over chicken skin.
Mix together cavilty ingredients and stuff into chicken cavity. Truss chicken shut.
Roast chicken for about 20 minutes per pound until internal breast temperature reaches 165 degrees and temperature between thigh reaches 170 degrees. Residual heat will rise temperature to 180 degrees at thigh. About 1 hour roasting time.
While chicken rests prepare gravy. Saute shallots in butter for about 1 minute until translucent. Add chicken stock, lemon juice, champagne, and rosemary. Simmer for about 4 to 5 minutes over medium heat to reduce volume. Stir in cream and capers. Heat thoroughly. Serve.