5
In a rectangular baking dish, spread 1/4 cup of the reserved enchilada sauce over the bottom. Layer 2 tortillas, followed by 1/3 of the shredded chicken, 1/3 of the black beans, 1/3 of the corn, 1/3 of the remaining enchilada sauce, 1/3 of the Monterey Jack cheese, and 1/3 of the cheddar cheese. Repeat this process for two more layers.