Sauté aromatics. Heat olive oil in a large pot over medium heat. Add onion and cook 3 to 4 minutes until softened. Add garlic and cook 30 seconds.
Brown the meat. Add ground meat, breaking it up as it cooks. Cook until browned. Drain excess grease if needed.
Season. Stir in taco seasoning and cumin and cook 30 seconds to bloom the spices.
Add the soup ingredients. Stir in beans, corn, Rotel, diced tomatoes, tomato sauce, and 3 cups broth.
Simmer. Bring to a gentle simmer and cook 15 to 20 minutes, stirring occasionally. Add more broth if you want it thinner.
Finish. Taste and adjust salt and pepper. Stir in lime juice if using.
Serve. Ladle into bowls and load up with toppings.