Preheat oven to 450°F. Line a large baking sheet with non-stick aluminum foil; set aside. Spray a 2 ½-quart or 9 x 13-inch baking dish with non-stick spray; set aside.
Add the bell pepper, zucchini, yellow squash, mushrooms and onion to the prepared baking sheet. Drizzle with olive oil; sprinkle with ¼ teaspoon salt, ¼ teaspoon pepper and Italian seasoning. Toss to thoroughly coat. Roast in preheated 450°F oven for 15 minutes or until vegetables are tender. Remove from oven; allow to cool slightly.
Reduce oven temperature to 375°F.
While vegetables are roasting, cook penne in salted water for 6 minutes. Drain in colander. (See Tip 8)
In a large bowl, gently toss the drained pasta, roasted vegetables, marinara sauce, ½ cup of fontina cheese, smoked mozzarella cheese, ¼ cup of parmesan cheese, green peas, remaining ¼ teaspoon of salt and ¼ teaspoon of pepper until well coated.
Transfer pasta mixture to prepared casserole dish. Top with remaining ½ cup of fontina cheese and ¼ cup of parmesan cheese. Dot with butter. May be prepared in advance up to this point. (See Tip 9)
Bake in preheated 375°F oven for 30 minutes or until cheeses are melted and mixture is bubbly.
Yield: 6 servings. (See Tip 10)