In a small bowl, combine the chicken, tomato, cucumber, feta, and red onion. Mix in the olive oil, vinegar, oregano, and salt/pepper if desired until well combined.
Spoon salad down center of bread, and wrap tightly.
SNAPPY TIPS: Instead of a flat bread, you could substitute a tortilla, gluten free bread, or even lettuce leaves.SNAPPY SUBSTITUTIONS: Instead of chicken, you could substitute precooked shrimp. Instead of oregano, you could use dill or other dried herbs.