Combine cornmeal and water in a small bowl; set aside.
Pour vegetable broth into a medium saucepan, and bring to a boil over high heat. Add cornmeal mixture in a slow, steady stream, stirring constantly. Stir in corn. Reduce heat to medium; cook, stirring constantly, 20 minutes or until mixture pulls away from sides of pan. Add 1/4 cup cheese and 1/4 teaspoon salt, stirring until cheese melts. Spoon into an 8-inch cakepan coated with cooking spray. Set polenta aside, and let cool completely.
Coat a large nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot. Add onion; saute until tender. Add garlic and crushed red pepper; cook 1 minute. Add mushrooms; saute until tender. Add wine and tomatoes; cook over medium-high heat, stirring constantly, until most of the liquid evaporates. Add parsley, basil, oregano, 1/4 teaspoon salt, and 1/8 teaspoon blackpepper. Set aside, and keep warm.
Turn polenta out onto a cutting board; cut polenta into 6 wedges. Place polenta wedges on a baking sheet coated with cooking spray. Coat polenta lightly with cooking spray. Broil 5 1/2 inches from heat (with electric oven door partially opened) 6 minutes or until crusty and golden. Place a polenta wedge on each individual serving plate.Top wedges evenly with mushroom mixture and remaining 1/4 cup Parmesan cheese. Serve warm.