In a large soup pot, add the beef and onions
Cook over medium-high heat until the beef is cooked and the onions are translucent
Drain - if necessary
Add beans, corn, diced and crushed tomatoes, taco seasoning, green chilies, and taco sauce
Bring the pot to a boil, reduce the heat
Simmer for about 20 minutes
Serve in bowls with toppings