1. Cook pasta according to package directions, omitting salt and fat. Drain.
2. Heat oil in a nonstick skillet over medium heat. Add chicken; cook 5 minutes.
3. Add onion, garlic, oregano, salt, pepper, and tomatoes to pan; cook 8 to 10 minutes.
4. Combine chicken mixture, pasta, and zucchini ribbons; toss gently. Top with Parmesan.