Heat olive oil in a large skillet over medium-high heat until shimmering. Season chicken strips with salt and pepper and lay flat in a single layer. Cook undisturbed for 3 minutes, flip, and cook another 2 to 3 minutes until cooked through with no pink center. Transfer to a plate and tent loosely with foil.

In the same pan, cook sliced onions for 2 minutes until softened. Add minced garlic and stir for 30 seconds until fragrant. Add herb blend, paprika, and chili flakes. Add bell pepper and cook for 3 minutes. Return chicken to the pan and toss for 1 minute. Fold in spinach and stir until wilted, about 45 seconds. Remove from heat and let cool for 5 minutes before assembling.

In a medium bowl, combine mozzarella and cheddar. Take two-thirds of the cheese mixture and blend with softened cream cheese, sour cream, and chives until smooth. Set the remaining one-third of dry shredded cheese aside.

Whisk melted butter and garlic powder together in a small bowl. Brush one side of each tortilla with the garlic butter. Flip tortillas buttered-side down on your work surface. Warm stiff tortillas for 10 seconds in the microwave first if needed.

Spread 2 tablespoons of creamy cheese blend in the center of each tortilla, leaving a 2-inch border. Add one-sixth of the cooled chicken mixture. Sprinkle 1 tablespoon of reserved dry cheese on top. Fold the bottom up, fold in both sides, and roll upward firmly. Press to seal and set aside seam-side down.

Heat a clean dry skillet over medium heat. Cook wraps seam-side down in batches for 2 to 3 minutes until golden brown. Flip and cook another 2 minutes until crispy and cheese is melted. Cover with a lid during the last minute for extra melt. Slice diagonally and serve immediately.