In a large skillet over medium-high heat, add the ground beef, diced onion, and minced garlic. Cook for about 6-8 minutes, stirring frequently, until the beef is browned and the onions are translucent. Drain any excess fat, ensuring a rich flavor base, and then transfer this savory mixture into your slow cooker.

To the slow cooker, add kidney beans, black beans, crushed tomatoes, diced tomatoes, and tomato paste. Pour in the beef broth, which adds moisture and depth to your Crockpot Chili. Stir gently but thoroughly to combine all the ingredients, ensuring even distribution for optimal flavor.

Sprinkle the chili powder, ground cumin, smoked paprika, black pepper, salt, oregano, and brown sugar over the mixture in the slow cooker. These spices will infuse your chili with warmth and complexity. Mix well again to incorporate all the seasonings thoroughly, creating a harmonious blend of flavors throughout the dish.

Cover the slow cooker with its lid, then set it to cook on LOW for 6-8 hours or HIGH for 3-4 hours. This gentle cooking allows the flavors to meld beautifully, resulting in a rich and hearty Crockpot Chili.

After the cooking time is complete, carefully lift the lid and check the chili's consistency. If it's too thick, stir in a bit more beef broth or water to achieve your desired texture. Taste and adjust salt or spices if needed, enhancing the flavor just before serving.

Ladle the warm, comforting Crockpot Chili into bowls. It’s perfect topped with shredded cheese, a dollop of sour cream, and a sprinkle of green onions for added freshness and creaminess.