• Preheat oven to 350°. Spray a 9 x 13" casserole dish with nonstick spray.
• Arrange the tortillas in a single layer in the casserole dish.

Make the Enchilada Sauce:

• Melt the butter in a medium pot. Whisk in the flour and make sure there aren't any clumps.
• Add the chili powder, cumin, and tomato sauce and whisk to combine.
• Add the chicken broth and bring to a boil. Whisk until the sauce thickens, remove from heat and set aside.

Make the Shredded Chicken:

• Heat the oil in a large pot or saucepan. Add the chicken thighs, season with salt, pepper, and chili powder. Sauté for 1-2 minutes. Flip and season the other side. Cover the thighs with chicken broth and bring to a boil. Boil until the chicken is cooked through and no longer pink in the center.
• Remove the chicken from the pot and use two forks to shred the chicken by pulling apart in opposite directions.

Assemble and Bake:

• Add a generous spoonful (about ¼ - ½ cup) of the enchilada sauce to each of the tortillas.
• Add the shredded chicken and black beans evenly to the tortillas. Add about 1-2 tablespoons of the shredded cheese.
• Close the tortillas and spread the top with remaining sauce. Sprinkle with remaining cheese.
• Bake for 20 minutes and serve warm.