Season chicken, if desired, with salt and ground black pepper.
Melt I Can't Believe It's Not Butter!® Spread in 12-inch nonstick skillet over medium-high heat and cook chicken, in batches, turning once, 2 minutes or until chicken is thoroughly cooked. Remove chicken and keep warm.
Cook onion in same skillet over medium-low heat, stirring occasionally, 2 minutes or until onion is tender. Stir in broth, scraping up brown bits from bottom of skillet. Stir in cream, mustard and maple syrup. Bring to a boil over medium-high heat. Reduce heat to medium and continue boiling 5 minutes or until slightly thickened.
Pour sauce over chicken and sprinkle with parsley to serve. If desired, serve with hot cooked rice.