Brown the Beef
In a large skillet over medium heat, cook the ground beef until browned and no longer pink. Drain excess fat if necessary.
Sauté the Vegetables
Add the diced onion, bell peppers, and garlic to the skillet. Cook for 3-4 minutes, until softened and fragrant.
Combine Ingredients in Slow Cooker
Transfer the beef and sautéed vegetables to the slow cooker. Add the beans, diced tomatoes, tomato paste, beef broth, chili powder, cumin, smoked paprika, salt, and black pepper. Stir to combine.
Cook
Cover and cook on low for 6-8 hours or on high for 3-4 hours. Stir occasionally if possible.
Serve
Ladle the chili into bowls and top with your favorite toppings, such as shredded cheese, sour cream, or chopped green onions.