01 - Lightly grease the inside of a 6 quart slow cooker with cooking spray or oil
02 - Place chicken breasts in the bottom of the slow cooker. Sprinkle evenly with cumin, chili powder, garlic powder, salt, and pepper on both sides
03 - Layer diced onion, red bell pepper, frozen corn, and drained black beans over the seasoned chicken
04 - Pour 1 cup of enchilada sauce evenly over the vegetable and bean mixture
05 - Arrange half of the tortilla pieces over the sauce mixture. Top with 1 cup of shredded cheese
06 - Repeat layers with remaining enchilada sauce, tortilla pieces, and remaining shredded cheese
07 - Cover and cook on low heat for 4 hours until chicken is cooked through and tender
08 - About 20 minutes before serving, shred chicken directly in the slow cooker using two forks. Mix thoroughly to combine all ingredients and cover to let flavors meld
09 - Serve hot bowls garnished with fresh cilantro, sliced green onions, and a dollop of sour cream if desired