Heat a large skillet over medium-high heat. Add the ground beef and cook until thoroughly browned, breaking it apart with a wooden spoon as it cooks. Drain any excess fat.

Transfer the browned ground beef to the crockpot. Add the diced bell pepper, diced yellow onion, and minced garlic.

Stir in the kidney beans, diced tomatoes with their juices, beef broth, chili powder, and ground cumin until well combined.

Cover the crockpot and cook on LOW for 6 to 8 hours, or on HIGH for 3 to 4 hours.

Serve hot and garnish with sour cream, shredded cheddar cheese, green onions, and fresh cilantro as desired.