Preheat your oven to 350°F (175°C).
Spray a 9 by 13-inch baking dish with cooking spray and set aside.
Heat 1 tablespoon of olive oil over medium heat in a large skillet.
Add diced onion and 1/2 teaspoon kosher salt; sauté until translucent, about 5 minutes.
Stir in chili powder and ground cumin, cooking for 30 seconds.
Add all-purpose flour, stir well.
Slowly whisk in chicken broth, then stir in tomato sauce and minced garlic.
Simmer, stirring occasionally, for 5 minutes. Optionally blend for smooth texture.
In a separate skillet, cook ground beef over medium heat.
Season with salt and black pepper. Add diced onion and cook until beef is browned, about 5 minutes.
Drain excess fat.
Stir in diced green chiles and black beans.
Mix in 1/2 cup enchilada sauce.
Pour 1/2 cup enchilada sauce into baking dish bottom.
Dip 6 tortillas in enchilada sauce, layer on bottom.
Spread half of beef mixture over tortillas.
Sprinkle 1 cup shredded cheese.
Dip remaining 6 tortillas in sauce, place on top.
Spread remaining beef mixture over tortillas.
Top with remaining 2 cups cheese.
Bake uncovered for 20 minutes until cheese is bubbly and golden.
Let cool slightly before serving.