01 -
In a large skillet over medium heat, brown the ground beef, breaking it into small pieces. If using, add diced onion, bell pepper, and garlic, sautéing until softened and fragrant.
02 -
Sprinkle the taco seasoning evenly over the cooked beef mixture. Pour in 1 cup of water and stir well to combine. Allow to simmer uncovered for 5 minutes to let flavors meld.
03 -
If using, stir in the diced tomatoes and black beans. Continue to simmer uncovered for an additional 5 to 10 minutes until the mixture thickens but remains moist.
04 -
Preheat oven to 350°F (175°C). Lightly grease a 9 x 13-inch baking pan to prevent sticking.
05 -
Place two tortillas evenly on the bottom of the baking dish. Spread half of the refried beans evenly over the tortillas, then layer half of the beef mixture atop the beans. Sprinkle one-third of the shredded cheese over the beef layer.
06 -
Cover the cheese layer with two more tortillas. Repeat spreading the remaining refried beans, beef mixture, and another third of the cheese evenly over this layer.
07 -
Place the final two tortillas over the layers. Distribute the remaining shredded cheese evenly across the top.
08 -
Cover the baking dish with aluminum foil and bake for 25 minutes to allow the cheese to melt and layers to heat through while keeping tortillas soft.
09 -
Remove the foil and bake uncovered for 10 more minutes, until the top cheese forms a golden, slightly crisp crust.
10 -
Let the casserole rest for 5 minutes before slicing to ensure clean portions. Serve with your choice of fresh toppings such as shredded lettuce, sour cream, salsa, and avocado.