The amount of the ingredients depends on how many you want to make, so I just wrote down what I used. Feel free to try other toppings!
Portobello mushroom caps
part-skim mozzarella cheese
green onions, chopped
sliced black olives
Preheat oven to 375 degrees. Place mushrooms on an ungreased baking sheet and bake (cap down) for 5 min. Remove from oven and add sauce, cheese, and toppings. Bake an additional 15 min. I also broiled mine for a minute or two to brown the cheese.
Original recipe found here.
The spaghetti squash boats. Mmm.