Season chicken with salt and pepper. Spray a pan with cooking spray over medium heat and sear chicken on both sides.
Add 4 tbsp. chicken broth and simmer until cooked through. Approx. 5 minutes (will vary depending on the thickness of your chicken).
Mix Dijon, milk, horseradish and chicken broth together in a bowl. Add Dijon cream sauce to the pan with the chicken and simmer for a few minutes. Cover chicken with cream sauce, top with 1 slice of ham and 1 slice of swiss cheese. Cover and cook until the cheese is melted.Serve with additional creamy Dijon sauce on top.