Heat olive oil in a large skillet over medium-high heat until shimmering. Season chicken strips with salt and pepper, place in single layer, and cook undisturbed for 3 minutes. Flip and cook another 2 to 3 minutes until internal temperature reaches 165°F. Transfer to plate and tent with foil.

In the same pan, add sliced onions and cook for 2 minutes until softened. Add minced garlic and sauté for 30 seconds until fragrant. Sprinkle in Mediterranean herb blend, paprika, and chili flakes, stirring to coat.

Add bell peppers and cook for 3 minutes until slightly softened. Return chicken to pan and toss to combine for 1 minute. Fold in spinach and stir just until wilted, about 45 seconds. Remove from heat and let cool for 5 minutes.

In medium bowl, combine mozzarella and cheddar. Measure out about 1⅓ cups of this mixture and blend with cream cheese and sour cream until well incorporated. Fold in chives. Reserve remaining ⅔ cup cheese for sprinkling inside wraps.

Whisk together melted butter and garlic powder in small bowl. Warm each tortilla for 10 seconds in microwave. Brush one side of each tortilla with garlic butter mixture, then flip so buttered side faces down.

Spread 2 tablespoons creamy cheese mixture in center of each tortilla, leaving 2-inch border. Top with about ⅔ cup chicken-vegetable mixture (one-sixth of total filling). Sprinkle 1 to 2 tablespoons reserved dry cheese over filling. Fold bottom edge up over filling, fold in both sides, and roll upward to create secure package. Set aside seam-side down.

Heat clean, dry skillet over medium heat. Working in batches of 2 to 3 wraps, place wraps seam-side down and cook 2 to 3 minutes until golden-brown. Carefully flip and cook another 2 minutes until crispy and cheese is melted. For extra gooey interior, cover pan with lid during last minute. Slice diagonally and serve immediately.