Optionally, apply nonstick spray to the slow cooker and place the chicken breasts at the bottom.
Add the enchilada sauce, fire-roasted tomatoes, green chiles, and taco seasoning, then stir gently.
Cover and cook on High for 3-4 hours or Low/Medium for 4-6 hours.
Once the chicken is tender, shred it using two forks or a stand mixer.
Return the shredded chicken to the slow cooker and mix in half of the shredded cheese, black beans, and corn.
Layer in the sliced tortillas and mix gently, then sprinkle the remaining cheese on top.
Cover and cook for an additional 20-30 minutes until the cheese is melted.
If desired, add cream cheese during the final cooking step for added creaminess.
Garnish with chopped cilantro before serving.
