Place the ground beef in a skillet along with the onions and cook until the beef is browned and the onions are tender.
Stir in the package of taco seasoning along with the amount of water indicated on the package directions. Cook for 8 to 10 minutes.
Add the Rotel, olives, and corn.
Spray the bottom of a 9×13-inch dish with nonstick spray. Place tortillas on the bottom of the dish. Spread half of the meat mixture evenly over the tortillas.
Sprinkle one cup of cheese over the meat layer. Then, add another layer of tortillas on top of the cheese.
Add the rest of the meat on top of the tortillas and the last cup of cheese on top of the meat.
Bake at 350°F until bubbly, about 20 minutes.
Serve with sour cream and other taco toppings as desired