01 - Whisk together olive oil, oregano, cumin, garlic powder, smoked paprika, salt, pepper, and lemon juice in a bowl. Add chicken breasts and turn to coat evenly. Let sit for 10 minutes while preparing other ingredients.
02 - Combine Greek yogurt, olive oil, lemon juice, minced garlic, dill, salt, and pepper in a small bowl. Whisk until smooth and creamy. Refrigerate until ready to serve.
03 - Grill or pan-sear marinated chicken over medium-high heat for 6 to 7 minutes per side until internal temperature reaches 165°F. Transfer to a cutting board and let rest for 5 minutes, then slice into thin strips.
04 - Heat a dry skillet over medium heat. Warm tortillas one at a time for 30 seconds per side until pliable and lightly toasted. Alternatively, wrap in damp paper towels and microwave for 30 seconds.
05 - Layer sliced chicken, shredded lettuce, tomatoes, cucumber, red onion, olives, and crumbled feta onto warmed tortillas. Drizzle generously with yogurt sauce and sprinkle with fresh parsley. Serve immediately.