PREPARATION:

1. Preheat oven to 400°F. Prepare Pastry Dough. While dough is resting, begin preparing vegetables for tart.
2. Spray nonstick baking sheet with cooking spray. Slice sweet potato into 1/4-inch-thick slices. Place on prepared baking sheet; spray tops of slices with cooking spray. Bake 15 to 20 minutes or until potatoes are tender, turning slices once.
3. Heat oil in large skillet over medium heat until hot. Add mushrooms, leeks, zucchini, parsnip, bell pepper, garlic, basil and rosemary; cook and stir 8 to 10 minutes or until vegetables are tender. Season to taste with salt and black pepper, if desired.
4. Roll out Pastry Dough on lightly floured surface to a 14-inch round; place on cookie sheet or large pizza pan. Place sweet potato slices evenly over crust, leaving a 2-1/2-inch border around side. Spoon vegetable mixture evenly over potatoes; sprinkle with cheese. Fold edge of dough over edge of vegetable mixture, pleating dough, as necessary, to fit. Brush edge of dough with egg white.
5. Bake 25 minutes or until pastry is golden brown. Garnish with fresh basil and rosemary, if desired. Cut into wedges; serve warm.