Stuffed Portobello MushroomsAdvertisementsAdvertisements Start Cooking (269 reviews)Prep:15 minsCook:25 minsTotal:40 mins Ingredients 4 large portobello mushroom caps, stems and gills removed1 tablespoon reduced-fat Italian salad dressing1 large egg1 clove garlic, mincedsalt and ground black pepper to taste1 (10 ounce) bag fresh spinach, chopped¼ cup chopped pepperoni¼ cup grated Parmesan cheese¼ cup shredded mozzarella cheese, divided¼ cup seasoned bread crumbs, dividedAdvertisements Start Cooking