Preheat and prep: Heat the oven to 375°F (190°C). Lightly oil a 9x13-inch baking dish.
Cut tortillas into halves or quarters so they layer neatly.
Brown the beef: Warm a large skillet over medium heat. Add the ground beef and cook, breaking it up, until no longer pink. Spoon off any excess fat if needed.
Add aromatics: Stir in the onion, bell pepper, and a pinch of salt.
Cook 4–5 minutes until softened. Add garlic and cook 30 seconds until fragrant.
Season the mixture: Add chili powder, cumin, smoked paprika, oregano, 1/2 teaspoon salt, and a few grinds of pepper. Toast the spices for 30–60 seconds to wake them up.
Build the filling: Stir in black beans, corn, diced tomatoes (drained), and tomato or enchilada sauce.
Simmer 3–5 minutes until slightly thickened. Taste and adjust salt and pepper. Stir in cilantro if using.
Layer the casserole: Spread a thin layer of the beef mixture on the bottom of the baking dish.
Add a layer of tortillas to cover. Spoon more beef mixture over the tortillas, then sprinkle a light layer of cheese.
Repeat: Continue layering—tortillas, beef mixture, cheese—ending with a modest layer of cheese on top. You’ll get about 3 layers depending on your dish.
Bake: Cover with foil and bake for 15 minutes.
Remove foil and bake another 10–12 minutes, until the cheese is melted and bubbly and the edges are hot.
Rest and serve: Let it sit 10 minutes so it sets for cleaner slices. Top with dollops of Greek yogurt, a squeeze of lime, and extra cilantro if you like.