01 - Preheat grill or grill pan to medium-high heat.
02 - Slice chicken breasts horizontally to create 4 thin cutlets.
03 - Combine chicken cutlets with olive oil, garlic powder, onion powder, paprika, salt, and black pepper in a bowl. Toss to evenly coat.
04 - Grill chicken cutlets for 4–5 minutes per side until the internal temperature reaches 165°F and juices run clear. Remove, let rest for 5 minutes, then slice into strips.
05 - In a small bowl, whisk together mayonnaise, sour cream, buttermilk, minced garlic, dill, parsley, lemon juice, onion powder, and season with salt and pepper until smooth.
06 - Heat pita breads briefly in a dry skillet or microwave until warm and pliable.
07 - Spread a generous spoonful of garlic ranch sauce inside each pita. Layer with romaine lettuce, cucumber, tomato, red onion, and sliced chicken. Drizzle with additional sauce as desired.
08 - Serve sandwiches immediately while warm.