Preheat oven to 350°F.
Remove the stems from the mushrooms. Scrape the gills out with a spoon. Gently wash the mushrooms and pat dry.
Place each mushroom on a rack inside a roasting pan. Fill with your choice of tomato sauce or brushetta and cheese. Sprinkle with dried oregano or other herbs if desired.
Bake for 15 minutes or until the mushroom is softened and the cheese is well melted. If desired, sprinkle with fresh basil or other herbs after removing from the oven.