Use Romano cheese instead of Parmesan if preferred, or use a combination of both.
Remove stems from mushrooms and reserve. Wash mushrooms and leave moist.
Combine half the cheese with the crumbs. Add garlic salt and black pepper to your preference. Roll the moist mushrooms in the cheese mixture; place cup side up on shallow non-stick baking pan sprayed with cooking spray.
Dry the stems and chop; add parsley and the remaining cheese. Spoon this mixture into the caps. Bake in preheated 475-degree oven 8-10 minutes or until browned.