Spray 10-inch nonstick skillet with cooking spray; heat over medium-high heat. Cook chicken and gingerroot in skillet, stirring occasionally, until chicken is brown. Reserve about 1/4 cup of remaining dressing mixture. Stir remaining dressing mixture into chicken. Cover and cook over medium-low heat 3 to 4 minutes, stirring occasionally, until chicken is no longer pink in center. Remove chicken from skillet.