This Pasta al Forno with Roasted Vegetables and is like a crusty, cheesy pasta primavera. It's very vegetable forward and uses a combination of simple, fresh ingredients with big flavors to yield the perfect pasta casserole for summer.
½cup(60 grams) freshly grated Parmigiano-Reggiano or Pecorino Romano cheese
To make the roasted vegetables: Heat the oven to 425°F and place the oven racks in the upper and lower third.
Combine the zucchini, eggplant, onion, and garlic in a large sheet pan. Pour 2 tablespoons olive oil over the vegetables, season with 2 teaspoons kosher salt and a generous grinding of pepper and toss to coat them thoroughly.
Cut the mushrooms into big pieces or thick slices and spread out in large sheet pan. Pour 3 tablespoons olive oil over the vegetables, season with 2 teaspoons kosher salt and a generous grinding of pepper and toss to coat thoroughly.
Place the pan of mushrooms on the top oven rack and the mixed vegetables on the bottom rack. Roast both for 15 minutes, then toss each with a spatula and return to the oven for another 15 minutes. Remove the pan of mushrooms after a total of 30 minutes. They should be tender and browned, and the ones around the edges of the pan are lightly crisped. Stir the mixed vegetables once more after the initial 30 minutes and roast for an additional 15 minutes, for a total of 45 minutes. They should be tender and nicely browned in spots. Set the roasted mushrooms and vegetables aside.
Reduce the oven temperature to 400°F. Lightly coat a 9-by-13-inch baking dish (3 ½ to 4 quart volume) with olive oil.
While the vegetables are roasting, bring a large pot of water to a boil over high heat and salt generously. Add the pasta, stir to separate, and cook according to manufacturer’s instructions until not quite al dente (it should be slightly underdone, because it will finish cooking in the oven). Drain the pasta in a colander, reserving about 1 cup of the cooking water. Return the drained pasta to the empty pot and set aside.
Put the grated tomatoes in a medium bowl and stir in the lemon juice, 1 tablespoon olive oil, and ½ teaspoon kosher salt.
Toss the pasta with the roasted vegetables and the roasted mushrooms. Add 2 cups of the tomato-lemon mixture and gently toss to combine thoroughly. Add a splash or two of pasta cooking water if needed to loosen up the sauce.
Spoon half of the pasta mixture into the prepared baking dish. Spread half of the sliced mozzarella over the pasta. Spoon the remaining pasta on top, and cover with the remaining mozzarella. Spoon the remaining tomatoes over the mozzarella and sprinkle the Parmigiano on top.
Cover the dish with greased foil (greased side down) and bake for 20 minutes, then uncover and bake for 20 to 25 minutes more, until the cheese is melted and bubbly and the top is nicely browned and crisp around the edges. Let stand for 5 minutes before serving.
To grate the tomatoes, cut them in half, trim the stem, scoop out the seeds with your fingers, and grate them with the cut side against the large holes of a box grater until only the skin is left in your palm. I recommend grating them directly into a bowl to catch all the juices.
If you have too much pasta and vegetables to fit in your baking dish, you can divide it up between a couple of baking dishes. Just fill the baking dish about halfway with pasta mixture, top with cheese, more pasta, etc. as the recipe instructs until you reach the top. Then repeat with the remaining ingredients in another (smaller) baking dish as needed.
To make ahead, roast the mixed vegetables and mushrooms and prepare the grated tomato sauce up to 2 days in advance and refrigerate in sealed containers. Then when you are ready, boil the pasta, mix, assemble and bake. Although you could assemble the entire casserole in advance and refrigerate before baking, the results will be better if you do it this way and it still saves a bunch of time day of.