Vegetables roast to tender sweetness in less than 20 minutes. When piled onto a polenta crust, the roasted asparagus, mushrooms, and tomatoes are sprinkled with Parmesan cheese for a meatless main dish.
Preheat oven to 400 degrees F. In a 15x10x1-inch baking pan, combine asparagus, mushrooms, tomatoes, and onion. Drizzle with olive oil and sprinkle with salt and pepper. Toss to coat. Roast for 18 minutes or until vegetables are just tender, stirring occasionally.
Meanwhile, coat a 10-inch tart pan with a removable bottom with nonstick cooking spray; set aside. Prepare Polenta as directed, except in Step 2 cook the polenta for 8 minutes. Stir in fontina cheese, snipped herbs, and garlic. Cook about 4 minutes more or until thick, but still creamy. Pour polenta into prepared tart pan, spreading evenly and smoothing the top with a thin metal spatula.
Top tart with roasted vegetables, arranging as necessary. Bake for 15 minutes. Sprinkle with Parmigiano-Reggiano cheese. Cool tart in pan on a wire rack for 30 minutes. To serve, carefully remove sides of tart pan. Cut tart into wedges. Serve warm. Makes 12 appetizer or side-dish servings.
In a large saucepan bring milk just to a simmer over medium heat. In a medium bowl combine cornmeal, water, and salt. Stir cornmeal mixture slowly into hot milk. Cook and stir until mixture comes to a boil. Reduce heat to low. Cook for 10 to 15 minutes or until mixture is very thick, stirring occasionally. (If mixture is too thick, stir in additional milk.) Stir in butter or margarine until melted.