Combine first 3 ingredients; sprinkle over chicken. Coat a nonstick skillet with cooking spray; place over medium-high heat until hot. Add chicken; cook 3 to 5 minutes on each side, or until browned. Remove chicken from skillet, and set aside.
Add wine to skillet; deglaze by scraping particles that cling to bottom. Combine flour and 1/4 cup milk, stirring until smooth; add to skillet. Stir in remaining 1/2 cup milk and mustard. Cook over medium heat, stirring constantly, until thickened. Return chicken to skillet. Bring to a boil; cover, reduce heat, and simmer 5 minutes or until chicken is done.