Heat 1 tablespoon olive oil in a medium skillet pan over medium heat. Add the onion and cook for 3-4 minutes, stirring occasionally.
Add the ground beef, sprinkle with 1 teaspoon of the salt, granulated garlic, cumin, chili powder, and paprika. Cook until browned and no longer pink. Drain any excess grease.
To a 6-quart slow cooker, add the cooked onion and ground beef, black beans, pinto beans, tomato sauce, diced tomatoes, green chilis, corn, and stock, stirring until well combined.
Cover and cook on high for 4-5 hours or low for 7-8 hours. Uncover and add the lime juice, stirring to combine. Taste and add additional salt or lime juice if desired. Serve with toppings of your choice.
Notes
Ground Beef: I prefer 90/10 lean ground beef so the soup doesn't end up with a layer of grease on top, but if you have 80/20 I just be sure to drain it well after browning.
Serving suggestions: Fresh cilantro, chopped onion, grated cheese (traditional or dairy-free), sour cream, corn chips, avocado, and hot sauce.