In a medium skillet heat the 2 tablespoons Italian salad dressing. Add asparagus and summer squash or zucchini; cook and stir for 2 minutes. Add mushrooms; cook and stir 1 minute more.
Place bread shells on a lightly greased or parchment-lined baking sheet. Brush bread shells with the 1/4 cup Italian salad dressing. Using a slotted spoon, top bread shells with the cooked asparagus mixture. Top with chopped tomato; sprinkle with pepper. Combine mozzarella cheese and Asiago or Parmesan cheese; sprinkle over pizzas.
Bake in a 400 degree F oven about 8 minutes or until cheese melts and pizzas are heated through. Cut the pizzas into wedges to serve. Makes 12 appetizer servings.