In a medium mixing bowl, combine shredded chicken, 1/2 cup of the taco blend (or cheddar), 1/2 cup of the mozzarella (or pepper jack), sour cream, diced green chiles (reserve 2 teaspoons for topping), and chopped cilantro; stir in 1/2 cup of the enchilada sauce until evenly mixed, and season with salt and pepper to taste.
Spread about 1/4 cup of enchilada sauce over the bottom of the slow cooker to prevent sticking.
Spoon about 1/4 cup of the chicken mixture down the center of each tortilla and roll up tightly.
Place the rolled enchiladas seam-side down in the slow cooker, arranging them snugly in a single layer; if needed, overlap slightly to fit.
Pour remaining enchilada sauce over the filled tortillas, then sprinkle the remaining taco blend and mozzarella (or pepper jack) cheese on top and scatter the reserved 2 teaspoons of diced chiles.
Cover and cook on HIGH for 60 to 75 minutes, until the sauce bubbles and the cheese is melted.
Carefully remove enchiladas from the slow cooker and serve; garnish as desired.