Add the ground beef to a large skillet over medium heat. Using a wooden spoon, break the meat apart and cook until browned. Drain off any excess grease. Transfer the beef to your crockpot.
Combine the beef broth, Rotel, black beans, pinto beans, corn, taco seasoning, and ranch seasoning in the crockpot.
Cover and set it to low for 3 to 5 hours.
Notes
The broth is intended to be on the thinner side, although it may thicken slightly due to the starches in the beans. If you prefer a thicker broth, blend a quarter cup of the beans and stir them back in, or mix a slurry of two tablespoons water with half a teaspoon of cornstarch and add it during the last 10 minutes of cooking.
Frozen corn works just as well as canned. Fire-roasted corn is a great option if you want to enhance the soup’s smoky flavor.
Using two cans of Rotel gives the soup a mild kick but is not overly spicy. If you are cooking for more sensitive palates, you can replace one can with petite diced or crushed tomatoes to mellow the heat while keeping the flavor.