Step 1

Preheat the oven to 375°F. Grease a 9x13-inch casserole dish with olive oil or nonstick spray.

Step 2

Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking up into small pieces, for 5 to 6 minutes, or until just a few pink spots remain.

Step 3

Add the onion and garlic, and cook for about 5 minutes until fragrant and slightly softened. Add the taco seasoning, ¾ cup (180mL) water, black beans, tomatoes, green chiles, salt, and pepper. Bring the mixture to a simmer, then reduce the heat to medium-low and cook for about 5 minutes, stirring frequently, until the mixture is steaming and the sauce coats the meat and vegetables. Remove from the heat.

Step 4

Place 1 cup of the meat mixture in the bottom of the casserole dish and spread into an even layer. Lay 6 of the tortillas over top in a single layer, overlapping slightly. Spread about one-third of the remaining meat mixture in an even layer and sprinkle all over with one-third of the cheese. Repeat the tortilla, meat, and cheese layers two more times.

Step 5

Cover with aluminum foil and bake for 25 minutes. Remove the foil and cook for 15 to 20 minutes more until the casserole is bubbling around the edges and the cheese is melty and lightly golden.

Step 6

Let rest for 10 minutes, then sprinkle with cilantro and sliced green onions. Serve pieces topped with diced tomatoes and sour cream.