Preheat the oven to 375°F (190°C).
Heat the olive oil in a skillet over medium heat, then add the chopped onion and red pepper and sauté until soft, about 5–6 minutes.
Add the shredded chicken, cumin, chili powder, smoked paprika, cayenne, and salt and pepper to taste; stir to combine.
Pour in half of the enchilada sauce, add the black beans and 1 cup of the shredded cheese, then heat and stir until warmed through and evenly combined.
Spray an 8×8-inch baking dish with nonstick spray and arrange two tortillas side by side to cover the bottom.
Spoon a portion of the chicken mixture over the tortillas, then add another layer of two tortillas and repeat layering until all filling and tortillas are used.
Top the assembled casserole with the remaining 1 cup of cheese and drizzle the remaining enchilada sauce over the top.
Bake for 25–30 minutes, until the cheese is melted and the casserole is heated through.
Let rest briefly, then garnish with cilantro and serve.
