1. Arrange oven rack 10 inches below broiler element. Preheat broiler to high.
2. Cook orzo according to package directions, omitting salt and fat. Drain and return to pan. Add parsley, oil, and 1/4 teaspoon salt; toss.
3. While orzo cooks, cut top and bottom off eggplant. Partially peel eggplant lengthwise with a vegetable peeler, leaving long purple stripes. Cut eggplant crosswise into 8 (1/2-inch-thick) slices; sprinkle with remaining 1/4 teaspoon salt. Place flour in a shallow dish. Combine 1 teaspoon water and egg in another shallow dish, stirring with a whisk. Combine panko, oregano, and Parmigiano-Reggiano in another shallow dish.
4. Dredge eggplant in flour, dip in egg mixture, and dredge in panko mixture, gently pressing mixture to adhere. Arrange on a baking sheet coated with cooking spray. Coat tops of eggplant slices with cooking spray. Broil 3 minutes on each side or until browned and tender but firm. Top evenly with mozzarella; broil 1 minute or until cheese melts.
5. Heat marinara in microwave at HIGH for 1 minute or until thoroughly heated. Arrange 1/2 cup orzo mixture on each of 4 plates; top each serving with 2 eggplant slices and 1/3 cup marinara. Sprinkle evenly with pepper.