01 -
Preheat oven to 175°C (350°F) and grease a 23x33 cm (9x13 inch) baking dish with cooking spray to prevent sticking and facilitate cleaning.
02 -
In a large skillet over medium heat, brown the ground beef and diced onion until the meat is no longer pink and the onions are softened, approximately 6-8 minutes.
03 -
Stir in minced garlic and cook for 1 additional minute until fragrant. Incorporate taco seasoning and water, stirring to combine evenly.
04 -
Add fire roasted diced tomatoes with their juices, green chiles, and drained black beans. Stir well and heat through for 3-4 minutes.
05 -
Arrange 6 corn tortillas at the base of the prepared dish, overlapping slightly to cover the bottom entirely. Spread one-third of the meat mixture over tortillas, then sprinkle 2 cups of the cheese blend evenly atop. Repeat this layering process two more times for a total of three layers.
06 -
Cover the dish tightly with aluminum foil and bake in the preheated oven for 30-40 minutes, until the casserole is bubbling at the edges and the cheese is thoroughly melted.
07 -
Allow the dish to rest for 10 minutes to set before slicing. Garnish with diced tomatoes, sliced green onions, and serve alongside dollops of sour cream.