Step 1

Preheat oven to 400 degrees. Spray a baking sheet with nonstick spray.

Step 2

Break each string cheese stick into thirds and place in a blender or food processor--blend at high speed until shredded. (Or pull into shreds and roughly chop.)

Step 3

Place mushroom caps on the sheet, rounded sides down. Bake until slightly tender, about 8 minutes.

Step 4

Remove sheet, but leave oven on. Blot away excess moisture from mushroom caps.

Step 5

In a small bowl, mix crushed tomatoes, garlic, and Italian seasoning. Divide mixture between mushroom caps, and sprinkle with cheese. Top with chopped mushroom stems, pepperoni, and olives.

Step 6

Bake until mushrooms are tender, filling is hot, and cheese has melted, 8 to 10 minutes. Enjoy!