In a large skillet over medium-high heat, break up the ground beef. Cook, stirring occasionally, until fully browned and no pink remains. Drain off any excess grease.

Push the beef to one side of the skillet or return to the skillet with 1 tbsp olive oil. Add the diced onion, bell pepper, and jalapeño (if using). Sauté until the onion is translucent and peppers softened, about 5-7 minutes.

Add the minced garlic, chili powder, cumin, smoked paprika, oregano, salt, and pepper. Cook, stirring constantly, for about 1 minute until fragrant.

Transfer the beef mixture to the slow cooker. Add the diced tomatoes (undrained), crushed tomatoes, tomato sauce, kidney beans, and black beans. Stir to combine.

Pour in the beef broth. Stir well and season with additional salt and pepper if needed.

Cover and cook on LOW for 6-8 hours or HIGH for 3-4 hours.

If thickening, mix 1 tbsp masa harina with 2 tbsp cold water to make a slurry. Stir into the chili in the last 30 minutes of cooking.

Taste and adjust seasoning. Serve hot with toppings like shredded cheese, sour cream, and cornbread.