Sauté onion: Heat a ~4 quart pot over medium heat. Once hot, add the oil and the onion and sauté over medium heat until softened, about 6 minutes.
Brown beef: Increase the heat to medium-high. Add the ground beef to the onion in the pot. Break up the beef and season with salt and pepper. Cook until browned and crumbled. Drain if desired.
Season: Reduce the heat to medium. Stir in the garlic for one minute, then stir in the tomato paste and taco seasoning until fully coating the beef mixture.
Add remaining ingredients: Add the diced tomatoes, beans, green chiles, corn and broth to the pot. Stir well, bring to a boil, then reduce to a good simmer. Cover and simmer for 15-20 minutes.
Serve: Check for seasoning, then serve the soup with your favorite toppings.