In a 3-qt. slow cooker, combine the chicken, enchilada sauce and chiles. Cover and cook on low for 6-8 hours or until meat is tender.
Remove chicken and shred with 2 forks. Reserve 1-2/3 cups cooking juices. Pour the remaining cooking juices into a large bowl; add the beans and shredded chicken. Coat 2 freezer-safe 8-in. square baking dishes with cooking spray; add 1/2 cup reserved juices to each.
Place about 1/3 cup chicken mixture down the centre of each tortilla. Roll up and place seam side down in prepared dishes. Pour remaining reserved juices over top; sprinkle with cheese.
Cover 1 dish and freeze for up to 3 months. Cover and bake second dish at 350° for 20 minutes. Uncover; bake until cheese is lightly browned, about 5 minutes longer. Serve with toppings as desired.
To use frozen enchiladas: Thaw in the refrigerator overnight. Remove from the refrigerator 30 minutes before baking. Bake as directed.