Coat a large nonstick skillet with cooking spray, place over med. heat until hot. Add chicken, and cook 7 min on each side until done. Set aside and keep warm. Melt margarine in a small saucepan over medium heat, add flour. Cook 1 minute stirring constantly with a wire whisk. Gradually add milk, stirring constantly. Stir in chives. Reduce heat to medium-low and cook, stirring constantly, 3 minutes or until thickened and bubbly. Add cheese, and stir until cheese melts. spoon over chicken 246 calories, 8.2g fat, 87mg cholestrol per serving