Heat the broiler. In a small bowl, whisk together 2 tablespoons of the oil with the vinegar, 1 teaspoon of the salt, and a few grinds of pepper and brush the mixture on the cut sides of the zucchini, eggplants, and onion. Arrange them cut-side up on a large, shallow baking pan.
Broil the vegetables 6 inches from the heat for 8 to 10 minutes on each side, until browned and fork-tender. Transfer to a cutting board. Cut the zucchini crosswise into thin slices. Cut the eggplant into 1-inch pieces. Chop the onion coarsely. BR] Meanwhile, in a large pot, cook the pasta according to the package directions. Drain in a colander. (Do not rinse.) Return the pot to the stove, add the garlic and the remaining oil, and cook over low heat until the garlic sizzles. Stir in the oregano and mint. Add the cooked pasta, broiled vegetables, chopped tomatoes, and Feta. Set aside half the pasta for Cheesy Vegetable Pasta, which is prepared before freezing. (See link to recipe, above.)
Season the rest of the pasta with the remaining 1/2 teaspoon salt and a few more grinds of pepper. Warm over low heat. Serve with the Parmesan.
To Freeze: Roasted-Vegetable and Feta Ziti does not freeze well as is. For best results, transform it into Cheesy Vegetable Pasta (see link to recipe, above). After preparation, cover with foil and freeze. It will keep frozen for 3 months.