Step 1

Heat oven to 375°F. Mist a 9×13-inch baking dish with cooking spray; set aside.

Step 2

Heat oil in a large sauté pan over medium-high heat.  Add onion and pepper and sauté for 6-7 minutes, or until softened.  Stir in the beans, corn, spinach, chicken, and 2 cups enchilada sauce, and stir until evenly combined.  Remove from heat and set aside.

Step 3

Pour about 1/2 cup of the remaining enchilada sauce in the baking dish, and spread until the bottom of the dish is evenly coated. Top with a layer of about 8 tortilla halves, so that the entire dish is covered. Top evenly with 1/3 of the chicken mixture, followed by 1/3 of the cheese.  Repeat with another layer of tortillas, chicken mixture, and cheese.  Followed by a final layer of tortillas, chicken mixture, the remaining 1/2 cup of enchilada sauce, and cheese.

Step 4

Cover the pan with aluminum foil, then bake for 20 minutes.

Step 5

Remove pan and remove aluminum foil. Uncover and bake for 10 more minutes, until the cheese is thoroughly melted.

Step 6

Remove from the oven and serve warm, garnished with your desired toppings.