Bell Pepper (Cored, Seeded, and sliced into 1/2 in strips • Onion • Skinless Chicken Breasts, rinsed and patted dry • Extra-Virgin Olive Oil • Dried Greek Seasoning Blend • Salt • Plain fat-Free Yogurt • Mayonnaise • Prepared Mustard (We used Regular Yellow Mustard) • Salt • Whole Round Pitas • Crumbled Feta Cheese •