For the vegetable filling, heat the oil in a large skillet. Add the zucchini, eggplant, mushrooms, carrots, and onions; cook, stirring, until softened, about 4 minutes. Stir in the 1/2 cups marinara sauce, the spinach, 1/2 cup Parmesan, the parsley, and salt. For the ricotta filling, in a large bowl, beat the egg; add the ricotta, 1 1/2 c mozzarella, and the pepper. In a small bowl, toss together 1/2 cup mozzarella and 1/4 cup Parmesan for the topping. Cook the noodles according to package directions; drain. Preheat the oven to 400F Thinly spread 3/4 cup marinara sauce in the bottom of a 9 X 13-inch baking dish. Use 4 of the noodles to line the bottom of the dish. Spread 1/2 of the ricotta filling over the noodles. Cover with 1/2 of the vegetable filling. Top with 4 more noodle. Spread with remaining ricotta filling and top with remaining vegetable filling. Top with remaining noodles. Spread remaining 3/4 cup marinara sauce over noodles. Bake, covered, 30 minutes. Sprinkle with cheese topping; continue baking 20 minutes longer. Remove from over and let stand 15 minutes before cutting into squares. Variation: You can vary the vegetables however you like-use more of some and less of others. Per serving: 782 Calories; 20g Fat (23% calories from fat); 37g Protein; 115g Carbohydrate; 70mg Cholesterol; 773mg Sodium Recipe by: 1000 Vegetarian Recipes Posted to EAT-LF Digest by Betsy Burtis on Feb 6, 1999,