I believe there is a typo in this recipe (Chicken Marsala).
The cooking steps do not mention neither the olive oil nor the cooking sherry. Perhaps you can substitute the olive oil for the butter and the cooking sherry for the marsala wine?
When I have had Chicken Marsala in restaurants it has always contained mushrooms. I have also prepared it and I know I used mushrooms. I also believe that I dipped the chicken in a flour mixture with spices, not breadcrumbs.
The Marsala wine is a MUST!!! It will not taste right without it.