Preheat the oven to 425 degrees F. Place vegetables in a bowl and toss with olive oil, basil, salt and pepper. Place on a large baking sheet and roast 20-30 minutes, or until vegetables are tender and lightly browned. Place vegetables in a pot and mix in diced tomatoes, tomatoes paste, stock and sugar. Bring to a gentle simmer, then loosely cover and cook, stirring occasionally, 25-30 minutes. 10 minutes before the sauce is ready, cook the pasta as per package directions. Drain well and divide among heated pasta bowls. Adjust the seasoning of the sauce, then spoon over hot pasta. Sprinkle with parsley. Serve with freshly grated Parmesan cheese, if desired.