Make dill yogurt sauce. Mix together yogurt with dill, garlic, and lemon juice. Season with salt and pepper and set aside.
Prepare spinach filling. Heat 2 tablespoons oil in a large saute pan over medium heat. Add sliced leek and season with salt and pepper. Continue to saute until caramelized, about 15 minutes. If pan becomes too dry, add a tablespoon of water.
Add scallions, mint, parsley, dill, and garlic. Saute for 1 minute. Add spinach, stirring to combine, and saute until spinach is wilted. Season filling with lemon zest, chili flakes, salt, and pepper. Remove from heat and add cream cheese and mozzarella, stirring until cheese is melted.
Fill each pita bread half with spinach filling. Sprinkle 1 tablespoon feta, 1 tablespoon olives, and 1 tablespoon of sun-dried tomatoes per wrap.
Heat a large saute pan over high heat. Lay pita pocket in pan and cook until toasted, about 1-2 minutes. Flip over and cook on the other side until toasted. Remove from heat and repeat with remaining pita pockets. Serve with dill yogurt sauce.