Cook seasoned chicken in oil till browned, then set aside. Cook mushrooms till tender. For the sauce, melt butter and cook garlic and onions. Add flour and cook till it thickens. (I averagely prefer to dilute it in a liquid, so it doesn't get lumpy!) Add broth, cream, parmesan, and seasoning. Add spinach and simmer for a few minutes. Add the chicken and mushrooms and serve over pasta or rice.