1. Heat oven to 400°F. Cut parsnips into 2- to 4-inch-long by ½-inch-thick sticks; toss with 1 tablespoon oil and ¼ teaspoon salt. Place on a rimmed baking sheet and roast 15 min.

2. Meanwhile, cut bell pepper into thin slices. Cut zucchini lengthwise in half, then into ¼-inch-thick slices. in a large bowl, toss together bell pepper, zucchini, remaining 2 tablespoon oil and ¼ teaspoon salt; add to roasting parsnips on baking sheet. Roast until tender and just golden, about 20 min. Remove from oven and let cool slightly.

3. Increase oven to 450°F and place rack in lower third. Sprinkle a baking sheet with 1 tablespoon cornmeal; set aside.

4. On a lightly floured surface, roll out half of the dough and, using, hands, stretch to ⅛-inch thickness. Transfer to prepared baking sheet. Top with half of each tomatoes, ricotta (in dollops) and roasted vegetables. Bake until cooked through and bottom is golden brown, 15 to 18 min. Repeat with remaining ingredients to make one more pizza.

5. Transfer pizzas to a cutting board, drizzle with oil and top with oregano.