In a large skillet, cook the ground beef and onion over medium heat until the ground beef is no longer pink and the onion is tender. Drain off the fat.
Add the enchilada sauce, black beans, diced tomatoes, corn, and olives. Bring the mixture to a simmer over medium heat, then simmer for 3-5 minutes or until the sauce thickens. Stir in 1 cup of the cheddar cheese until completely melted.
Assemble the nachos by spreading out half of the tortilla chips on the bottom of a large platter or large sheet pan. Top with half of the sauce, followed by ½ cup of the remaining cheddar cheese. Repeat the three layers one more time, finishing off with the last ½ cup of cheddar cheese.
Top with any additional toppings you would like and serve immediately.