Cook the whole wheat pasta according to package instructions until al dente. Drain and rinse under cold water to cool. Set aside.
In a large mixing bowl, combine the cherry tomatoes, cucumber, bell pepper, cooked chicken, feta cheese, and red onion.
In a small bowl, whisk together the olive oil, red wine vinegar, garlic powder, dried oregano, salt, and pepper.
Add the cooled pasta to the vegetable and chicken mixture. Pour the dressing over the salad and toss gently to combine all ingredients.
Taste and adjust seasoning if necessary. Chill in the refrigerator for at least 30 minutes before serving to allow flavors to meld.
Serve the pasta salad garnished with fresh parsley.