Sweet Potato Fries

3 large sweet potatoes1/4 C italian dressing1/4 C grated Parmesan CheesePreheat oven to 425. Scrub potatoes well but do not peel. Cut each in half across the width, and cut into spears; Transfer to a large bowl and toss with dressing. Place on a lightly greased baking sheet in a single layer. Bake 12 minutes. Turn with large spatula. Continue to bake10-15 minutes, sprinkling parmesan chesse on last 5 minutes. Sprinkle with salt and serve with sour cream.