Start by placing the chicken breasts at the bottom of your slow cooker. Pour in about half of the enchilada sauce, then add diced tomatoes, onion, garlic, and spices. This creates a flavorful base for the chicken to cook in.
Cover and cook on low for 6–7 hours or high for 3–4 hours. The chicken should be tender enough to shred easily with a fork. This slow cooking process helps absorb all the spices and sauce.
Once cooked, remove the chicken and shred it using two forks. Return it to the slow cooker and mix it well with the sauce. Add corn and black beans at this stage for added texture and flavor.
Add a layer of tortilla strips on top of the chicken mixture. Sprinkle cheese over it, then repeat the layering process. This creates that classic enchilada-style structure right in the slow cooker.
Cover and cook for another 30–40 minutes until the cheese is melted and everything is heated through. This final step brings all the layers together beautifully.