This is my mushroom twist on eggplant parmesan. 

-6 portobello mushrooms, cleaned
-one recipe of my homemade marinara sauce or one jar of your favorite brand
-salt and pepper
-2 cups shredded mozzarella cheese

Cover bottom of 13×9 dish with half of sauce.  Place mushrooms (gill side up) in dish.  Sprinkle mushrooms with salt and pepper.  Cover mushrooms with remaining marinara sauce.  Bake at 400 for 25 minutes.  Sprinkle cheese over mushrooms and bake 5 more minutes, or until cheese is melted.