1. Cook spinach in a lightly greased large nonstick skillet over medium-high heat, stirring often, 2 minutes or until wilted. Transfer spinach to a bowl.
2. Combine flour, salt, and pepper in a shallow dish; dredge chicken in flour mixture.
3. Melt butter in skillet; add chicken, and cook 4 to 5 minutes on each side or until golden and done. Remove chicken from skillet, reserving drippings in skillet.
4. Add chicken broth and next 4 ingredients to skillet, and bring to a boil, stirring to loosen particles from bottom of skillet. Cook, stirring occasionally, 2 minutes or until reduced by half. Stir in spinach, and cook 1 minute or until thoroughly heated. Serve chicken over spinach mixture. Garnish, if desired.