Brown 1 pound ground beef in a large skillet over medium heat until cooked through, then drain off any excess fat.
Add 2 tablespoons taco seasoning, 1 can chili beans, 1 can Rotel (diced tomatoes with green chilies), and 1 can (15 oz) crushed tomatoes to the skillet with the ground beef and stir to combine.
Spray a 9x13 casserole dish with cooking spray and place a layer of 12–16 corn tortillas cut into quarters on the bottom of the dish.
Pour half of the meat mixture over the tortillas, sprinkle with 1 cup of the 2 cups shredded cheddar cheese, place another layer of the remaining corn tortillas on top, pour the remaining meat mixture over the tortillas, spread 1 cup sour cream over the top, and sprinkle with the remaining 1 cup shredded cheddar cheese.
Bake at 350 for 20 minutes or until cheese is nice and bubbly.