I use cornflake crumbs to make it gluten free, and I also used prepared pesto in a tub to make it even easier. I prefer fresh mushrooms as well.
Spray 9x12 dish with no stick spray
Prepare pesto sauce mix according to directions
Place chicken in baking dish
Cover each breast with half slice of provolone
Spread mushrooms on top
Bake in oven 45 -50 mins