Preheat oven to 375℉. Gather the ingredients so you have everything close at hand on the counter or table.
Prepare the Ingredients
Using a knife and cutting board, chop 1 cup sweet onion. Mince 2 tablespoons garlic.
With a handheld shredder, grate 8 oz. cheddar cheese.
Brown the Meat
In a large skillet, brown 2 1/2 pounds lean ground beef and sauté the chopped onion and minced garlic until tender. Add 2 teaspoons soy sauce, 2 teaspoons chili powder, 2 teaspoons ground cumin, 1 teaspoon dried oregano, 1 teaspoon kosher salt and 1 teaspoon freshly ground black pepper.
Prepare the Sauce
In a large bowl, combine 20 oz Enchilada Sauce, 10 oz. chopped green chilis, 10.5 oz. cream of mushroom soup, and 15 oz. black beans.
Assemble the Casserole
Spray an oblong baking pan with cooking spray. Pour 1/2 cup of enchilada sauce mixture on the bottom of the pan. Place a layer of 25 oz corn tortillas over that and top with 1/3 beef mixture, 1/3 sauce, and 1/3 cheese. Repeat layers two more times.
Cover and bake in preheated oven for 25 minutes. Uncover and bake another 10-15 minutes until cheese is lightly browned and bubbly. If desired, serve with lettuce, tomatoes, sour cream, and guacamole. Serves 8-10.