In a skillet over medium heat, brown the ground beef until fully cooked. Drain excess fat and transfer to the slow cooker.
Add the diced onion and minced garlic to the skillet. Sauté until the onion becomes translucent, then add to the slow cooker.
Stir in the black beans, corn, diced tomatoes, nacho cheese soup, beef broth, taco seasoning, cumin, salt, and pepper into the slow cooker. Mix until well combined.
Cover the slow cooker with its lid and set it on low for 4 hours.
About 30 minutes before serving, stir in the shredded cheddar cheese and let it melt into the soup.
Once done, taste and adjust seasoning if necessary.
Serve hot with tortilla chips and your choice of toppings.