French Onion Baked Chicken

    1     tablespoon olive oil
    4     boneless, skinless chicken
          breasts

Caramelized Onions:
    2     tablespoons butter
    1     tablespoon olive oil
    3     medium sweet onions, sliced
    1/2     teaspoon salt
    2     sprigs fresh thyme
    3     garlic cloves, minced
    1     tablespoon balsamic vinegar
    1     tablespoon Worcestershire
    2/3     cup beef broth
    2     teaspoons Dijon mustard
    1     cup shredded mozzarella,
          gruyere or fontina cheese

    Preheat oven to 400 F. In large pan over medium-high heat, heat oil. Sear chicken breasts 2-3 minutes on each side. Remove from pan.
    To make caramelized onions: In separate pan over medium-high heat, heat butter and olive oil. Once butter is melted and bubbling, add onions. Let sit 5 minutes.
    Turn heat to low and cover onions. Cook 20 minutes, stirring halfway through.
    Stir in salt, fresh thyme and garlic; cover onions. Cook 10 minutes.
    Stir in balsamic vinegar, Worcestershire, beef broth and Dijon mustard. Cover and cook 10-15 minutes, or until onions are brown and jammy. Stir onions every 10 minutes.
    Place chicken breasts in greased baking dish. Top with onions then cheese. Place any additional onions in bottom of dish.
    Bake 30-35 minutes, or until chicken reaches internal temperature of 165 F.