Lightly grease the inside of a 6-quart slow cooker with non-stick cooking spray.

Place the chicken breasts in the bottom of the slow cooker. Sprinkle with ground cumin, garlic powder, dried oregano, salt, and black pepper.

Add the diced red bell pepper, diced zucchini, black beans, corn kernels, and pour the enchilada sauce over the top.

Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the chicken is tender and fully cooked.

Remove the chicken breasts from the slow cooker, shred them using two forks, and return the shredded chicken to the slow cooker.

Add the tortilla strips to the slow cooker and stir to combine all ingredients thoroughly.

Sprinkle 1 cup of shredded cheddar cheese over the mixture and stir until melted and well incorporated.

Flatten the mixture evenly in the slow cooker and sprinkle the remaining 1 cup of shredded cheddar cheese over the top.

Cover and cook on low for an additional 30-40 minutes, until the cheese is melted and bubbly.

Serve the casserole warm, garnished with optional toppings such as chopped fresh cilantro, sliced jalapeños, sour cream, or diced avocado.