Portobello pizzas are so easy to make, and you can add whatever toppings you like. The one pictured below is a basic version with tomato sauce, Italian seasoning, and mozzarella cheese. These do need to be enjoyed with a knife and fork though, especially since I always use extra sauce.
First, bake the mushrooms on a cookie sheet coated with cooking spray for 10 minutes at 400F. Then, add the toppings and bake for an additional 10-15 minutes at 400F.