Preheat oven to 400° In a 13x9 baking dish, toss the sweet potato, white potato and carrots with 1/4 cup vegetable broth, salt and pepper until evenly coated. Spread the potatoes and carrots evenly across the bottom of the pan.
Place the onion slices evenly atop the potato mixture, followed by the bell pepper, zucchini and squash. Drizzle with another 1/4 cup of the vegetable broth.
Place the tomato slices over the zucchini and squash. Drizzle the tomato slices with half of the remaining veggie broth. Bake uncovered for 30 minutes.
In a small bowl, combine the Param Zaan (or regular grated Parmesan if using) and the bread crumbs. After the casserole has cooked for 30 minutes, remove casserole from oven and sprinkle with the Parma Zaan and breadcrumbs mix. Drizzle with the remainig veggie broth and cook for an additional 10 minutes.