Scale

1 tablespoon olive oil

1 medium white onion, peeled and diced

1 large poblano or green bell pepper, cored and diced

2 (15-ounce) cans beans, rinsed and drained (pinto or black beans)

1 (8-ounce) can whole kernel corn, drained

2 handfuls fresh baby spinach

3 cups cooked chicken, shredded or diced (about 1.5 pounds)

3 cups green enchilada sauce (or salsa verde)

12 corn tortillas, halved

3 cups shredded Monterrey Jack or Mexican blend cheese

Optional Toppings: fresh cilantro, diced red onion, sliced green onion, avocado

Heat the Oven: Preheat oven to 375°F. Mist a 9×13-inch baking dish with cooking spray.
Cook the Filling: In a large sauté pan, heat olive oil over medium-high heat. Add onion and pepper. Sauté for 6–7 minutes until softened. Stir in beans, corn, spinach, chicken, and 2 cups enchilada sauce. Mix well, then remove from heat.
Layer the Casserole: Spread ½ cup enchilada sauce evenly on the bottom of the prepared dish. Arrange about 8 tortilla halves to cover the base. Top with ⅓ of the chicken mixture and ⅓ of the cheese. Repeat with another layer of tortillas, filling, and cheese. For the final layer, add tortillas, remaining filling, ½ cup sauce, and the rest of the cheese.
Bake Covered: Cover with foil and bake for 20 minutes.
Bake Uncovered: Remove foil and bake uncovered for 10 more minutes, until cheese is melted and bubbling.
Rest and Serve: Let casserole rest for 10 minutes. Garnish with toppings like avocado, cilantro, or onions before serving.