How to Make It
Preheat the oven to 350°. Cook the rigatoni in a large pot of boiling salted water, stirring occasionally, until al dente. Drain the pasta, reserving 1/4 cup of the cooking water. Return the pasta to the pot while preparing the sauce.
Puree the tomatoes with their juices in a blender or food processor. Pass the puree through a fine sieve set over a bowl to remove the seeds.
Heat 1/4 cup of the vegetable oil in a large nonstick skillet. Line a large plate with paper towels. Add half of the eggplant to the skillet and cook over moderately high heat, stirring occasionally, until golden brown, about 6 minutes. Using a slotted spoon, transfer the eggplant to the plate to drain. Repeat with the remaining eggplant and vegetable oil and add to the first batch of eggplant. Discard the oil in the skillet.
Heat the olive oil in the same skillet used to cook the eggplant. Add the garlic and cook over moderate heat, stirring occasionally, until fragrant, about 30 seconds. Add the zucchini and onion and cook over high heat, stirring often, until slightly softened, about 6 minutes. Add the tomato puree, basil and oregano and simmer over moderate heat until the sauce is reduced by one-third, about 15 minutes. Stir in the eggplant and season with salt and pepper.
Fold the eggplant and zucchini sauce into the rigatoni along with the mozzarella and the reserved pasta cooking water. Transfer the pasta to a 9-by-13-inch baking dish and sprinkle the Parmesan cheese evenly over the top. Bake for 15 minutes, or until heated through. Serve the pasta piping hot.