In medium saucepan over medium-high heat, bring water, 2 teaspoons salt and 1 teaspoon pepper to a rapid boil. Slowly whisk polenta into water until incorporated. Reduce heat to low; continue stirring until thickened (about 3-4 minutes). Fold in 1/2 cup Asiago cheese and 1 teaspoon each parlsey and thyme. Spray 9x13-inch baking dish with no stick cooking spray; spread polenta into prepared baking dish. Set aside. Heat oil in Dutch oven over medium-high heat. Add onion, peppers, celery, carrot, cayenne and remaining salt and pepper. Saute, stirring frequently until onions are translucent (about 8-10 minutes). Add tomatoes, corn and garlic. Cook until almost all of the liquid is evaporated and vegetables are tender (about 9-11 minutes). Stir in turkey (optional), 3 teaspoons thyme and 3/4 cup Asiago cheese. Spread ratatouille over polenta. Sprinkle remaining cheese over ratatouille. May be refrigerated, covered, several hours or overnight.