Coat eggplant slices with flour. Saute in oil until browned and tender. Drain and dice. Combine ziti, eggplant, ricotta, parmesan or romano, shredded mozzarella and 1/4 cup of marinara sauce. Spoon into lightly greased shallow individual Au Gratin dish. Bake at 325 ° for 15 minutes. Remove form oven. Top with rest of marinara sauce and sliced cheese. Broil, 4" from heat source until cheese is melted.