01 - In a large skillet over medium heat, brown the ground beef until no longer pink, breaking it up with a spoon. Drain excess fat.
02 - Move the cooked ground beef to the slow cooker.
03 - Add chopped onion, diced red and green bell peppers, minced garlic, diced tomatoes with their juices, tomato paste, kidney beans, black beans, and beef broth into the slow cooker.
04 - Stir in chili powder, ground cumin, smoked paprika, dried oregano, optional cayenne pepper, salt, and black pepper.
05 - Mix all ingredients thoroughly to ensure even distribution of flavors.
06 - Cover and cook on Low for 6 to 8 hours or on High for 3 to 4 hours.
07 - Taste and adjust seasonings if necessary before serving.
08 - Serve hot topped with desired optional ingredients such as cilantro, shredded cheddar, sour cream, avocado, or jalapeños.