1. Heat oven to 425 degrees F. Combine tomatoes, onions and 1/4 cup oil in a 13x9x2-inch glass baking dish. Roast, uncovered, about 30 minutes, until tomatoes blister. Transfer tomatoes to a bowl. Continue roasting onions 10 to 15 minutes more, until golden. Transfer onions and accumulated juices to bowl with tomatoes. Do not wash baking dish. Coarsely chop the vegetables. Set aside.
2. Meanwhile, cook pasta 2 minutes less than package directions. Drain and toss with vegetables and 1/4 teaspoon of the salt. Spoon into baking dish.
3. Heat remaining 1 tablespoon oil in a medium saucepan over medium-high heat. Add garlic and shallots; cook 30 seconds. Stir in wine and cook until liquid reduces by half, 3 minutes. Add cream, stirring until mixture thickens, 5 minutes. Remove from heat. Stir in cheeses until melted; add remaining 3/4 teaspoon salt and the pepper.
4. Pour sauce over pasta, stirring to coat. Cover with foil and bake until sauce is bubbly, 35 to 40 minutes. Stir pasta until well coated. Sprinkle the top with chopped parsley, if desired. Makes 6 servings.