In a bowl, combine olive oil, minced garlic, dried oregano, ground cumin, salt, and pepper. Add chicken breasts and marinate for at least 30 minutes.

Preheat grill or skillet over medium-high heat. Cook marinated chicken for 6-7 minutes on each side until the internal temperature reaches 165°F. Let rest for 5 minutes before slicing.

Whisk together plain Greek yogurt and lemon juice in a small bowl until smooth and creamy. Adjust lemon juice to taste.

In a large mixing bowl, combine diced tomatoes, diced cucumber, finely chopped red onion, Kalamata olives, and crumbled feta cheese. Toss until well mixed.

Heat a dry pan over medium heat and warm the tortillas for about 30 seconds on each side.

Layer sliced grilled chicken on a warm tortilla, add salad topping, and drizzle with yogurt sauce. Garnish with freshly chopped parsley.

Serve immediately to enjoy while warm and flavorful.