Combine peppers, onion, tomato sauce, sage if using, basil and oregano in skillet. Simmer, covered, 5 minutes. Uncover; cook 3 minutes until sauce is thickened. Cool.
Coat 12-inch pizza pan with cooking spray. Roll dough out to 13-inch circle on floured surface. Fit into prepared pizza pan.
Bake crust in preheated 450 degree F oven 10 minutes. Spread sauce mixture evenly over top, leaving 1-inch border. Sprinkle on mozzarella, mushrooms and Parmesan. Return pizza to oven. Bake 12 minutes until golden. Cool 10 minutes. Makes 4 servings.