Preheat oven to 450 degrees. Trim mushrooms; cut into thin slices (makes about 3 cups). Cut bell pepper in thin strips. Sprinkle 1/2 cup fontina over pizza shell. In a large bowl, combine mushrooms, pepper strips, Parmesan and salad dressing until well blended; scatter over pizza shell.

Sprinkle with remaining 1 cup fontina. Bake until mushrooms are tender and cheese has melted, 10 to 12 minutes. Top with chopped parsley, if desired. Variations: In addition to or in place of the red bell pepper, use 1/2 cup thinly sliced plum tomatoes, green onions or pepperoni.