Heat a Dutch oven or large soup pot over medium-high heat. Add the ground beef and cook for about 5 minutes, breaking it into crumbles. While the beef is still slightly pink, add the onion, carrots, and celery.
Cook for another 5–7 minutes, stirring occasionally, until the beef is browned and the vegetables begin to soften. Drain excess grease if needed, leaving a little in the pot.
Stir in the tomato paste and cook for 1 minute. Add the garlic and taco seasoning and cook, stirring, for about 30 seconds.
Gradually stir in the beef stock, scraping up any browned bits from the bottom of the pot. Add the tomatoes, green chilies, black beans, pinto or kidney beans, and corn.
Bring to a gentle boil, then reduce the heat and simmer uncovered for 12–15 minutes, stirring occasionally, until the carrots and celery are tender and the broth has thickened slightly.
Taste and adjust the seasoning as needed. Serve hot with your choice of toppings.
Notes
Finely dice the carrots and celery so they soften within the short cooking time.
My copycat taco seasoning packet contains cornstarch, which gives the broth a little body without a separate thickener. Other taco seasoning blends may produce a thinner broth.
You can use two cans of black beans or change up the combination with pinto or kidney beans.