Spray 12-inch pizza pan with nonstick cooking spray. Unroll crust; press onto prepared pan. Bake in preheated 425°F oven 6 minutes or until crust is just beginning to brown.
Spray skillet with nonstick cooking spray; stir in onion and garlic. Cook over medium heat 2 minutes until onion is soft. Add pepper and mushrooms; cook 2 minutes. Remove from heat; set aside.
Sprinkle 3/4 cup cheese over crust. Arrange tomato slices over cheese; sprinkle with basil and oregano. Top with mushroom mixture and remaining cheese. Bake in preheated 425°F oven 10 minutes or until crust is crisp and cheese is melted.