Heat the olive oil in a large soup pot over medium heat until shimmering, then add the diced onion and cook until it becomes soft and translucent, about 3-4 minutes.
Add the ground meat to the pot and cook, breaking it apart with a wooden spoon, until browned and cooked through, about 6-8 minutes. Drain excess fat if needed.
Stir in the minced garlic and cook for 30 seconds until fragrant, filling the air with a savory aroma.
Add the diced tomatoes (with juice), black beans, corn, and taco seasoning to the pot, stirring everything together thoroughly.
Pour in the broth and bring the mixture to a gentle boil, then reduce the heat to low and let it simmer uncovered for about 20-25 minutes, allowing flavors to meld and the soup to thicken slightly.
Season with salt and pepper to taste, then ladle the hot, hearty soup into bowls and garnish with your favorite toppings like shredded cheese, chopped cilantro, or a squeeze of lime.
