Preheat oven to 425°F; line 2 large baking sheets with foil. Combine carrots, parsnips, sweet potato and squash in a large bowl. Add olive oil, thyme, salt and pepper, and toss to coat.
Divide vegetables between baking sheets and roast, stirring twice, until golden brown and tender, 35 to 40 minutes. Season with additional salt and pepper, if desired. Serve hot.
This recipe also appeared in the January 2011 issue.