Preheat your oven to 375°F (190°C). Lightly spray a standard 9×13-inch glass or ceramic baking dish with non-stick cooking spray and set it aside.

Heat a large skillet over medium-high heat. Drop in the lean ground beef, diced yellow onion, and diced green bell pepper. Cook for 5 to 6 minutes, breaking the meat up with a firm wooden spoon, until the beef is fully browned and the vegetables are soft. Drain away any heavy pooling grease from the pan.

Reduce the skillet heat to medium-low. Sprinkle the taco seasoning packet uniformly over the beef mix, pour in the ¼ cup of beef broth or water, and stir thoroughly. Let it simmer uncovered for 2 to 3 minutes until the liquid reduces and coats the meat. Remove from the heat.

In a large mixing bowl, combine the condensed cream of chicken soup, condensed cream of mushroom soup, sour cream, and the full undrained can of diced tomatoes with green chilies. Whisk firmly with a fork until the elements combine into a uniform, rich savory sauce baseline.

Arrange half of your cut corn tortilla pieces in an even, overlapping layer across the entire bottom of the prepared baking dish to form the base crust.

Spoon half of the seasoned ground beef mixture directly over the tortilla layer, then pour half of the creamy soup sauce baseline uniformly over the meat. Scatter exactly 1 cup of the shredded cheddar cheese across the top.

Repeat the layers one more time: arrange the remaining corn tortilla pieces, top with the rest of the ground beef, and spread the remaining cream sauce baseline evenly over the surface.

Scatter the remaining 1 ½ cups of shredded cheddar cheese uniformly across the very top of the casserole.

Place the dish uncovered on the middle oven rack and bake at 375°F for 25 to 30 minutes. The casserole is finished the exact moment the interior sauce is bubbling fiercely around the inner borders of the pan and the top cheese layer is entirely melted, gooey, and lightly golden.

Remove the baking dish from the oven and let it sit flat on a cooling rack for 10 minutes before scooping. This brief resting window allows the tortilla starches to finish binding with the fats so it holds its shape beautifully when served. Garnish with fresh chopped cilantro and serve hot.