Combine breadcrumbs and cheese in a small bowl, stirring well. Brush both sides of each chicken breast half with mustard; dredge in breadcrumb mixture.
Place chicken on rack of a broiler pan coated with cooking spray. Broil 5 1/2 inches from heat (with electric oven door partially opened) 5 minutes on each side or until chicken is done. Serve immediately.
Cooking Light Low-Fat, Low-Calorie Quick and Easy Cookbook