Gather all ingredients and equipment, ensuring everything is ready to go.
Heat the large pot over medium heat until warm and add the diced onion, sautéing until translucent and fragrant, about 5 minutes.
Add the minced garlic to the onions and cook for another minute until the aroma fills the air.
Push the vegetables to one side of the pot and add the ground meat, breaking it apart with your spoon or spatula, cooking until browned and no pink remains, about 7 minutes.
Stir in the canned diced tomatoes, drained beans, corn, and taco seasoning, mixing well to combine all the flavors.
Bring the mixture to a gentle simmer, reduce heat to low, and let it cook uncovered for about 20 minutes, stirring occasionally to meld the flavors.
Taste the soup and adjust seasoning as needed with extra taco seasoning or salt for more flavor.
Once ready, ladle the hot soup into bowls and sprinkle generously with shredded cheese, a dollop of sour cream, and chopped cilantro for freshness.
Serve immediately while warm and enjoy the comforting, hearty flavors.