Get your oven heating to 350°F and give a 2-quart baking dish a thorough coating of cooking spray. This prevents sticking and makes cleanup much easier later.
Warm the oil in a large skillet over medium heat. Crumble in the ground beef and cook for 6-8 minutes, breaking it apart with a wooden spoon as it browns. You want it fully cooked with no pink remaining.
⏱ 8 min
Sprinkle the taco seasoning over the beef along with salt and pepper to taste, then fold in the drained beans. Stir everything together so the seasoning coats evenly.
Pour ¼ cup of the enchilada sauce across the bottom of your prepared baking dish and spread it around with a spoon. This sauce layer prevents the tortillas from sticking.
Arrange one-third of the tortilla halves over the sauce, overlapping them slightly to cover the bottom completely.
Spread half of the beef and bean mixture over the tortillas, then sprinkle ¾ cup of the cheese on top. The cheese helps bind each layer together.
Drizzle ½ cup of enchilada sauce evenly over the cheese layer. Don't worry about perfect coverage — it will spread as it bakes.
Build your second layer: another third of the tortillas, the remaining beef mixture, another ¾ cup of cheese, and another ½ cup of sauce. Press gently to compact the layers.
Finish with the final tortillas, pour the remaining enchilada sauce over everything, and top with the last of the cheese. The top should look generous and well-covered.
Cover tightly with foil and bake for 30 minutes. Remove the foil and continue baking 5-10 minutes longer, until the cheese is melted and starting to brown at the edges.
⏱ 40 min
Scatter the diced tomatoes and green onions over the hot casserole for fresh color and flavor. Let it rest for 5 minutes — this settling time makes it much easier to cut clean squares.
⏱ 5 min