In a large pot or Dutch oven, heat a little oil over medium heat. Add the ground beef and cook until browned, breaking it up with a wooden spoon, about 5-7 minutes.
Add the diced onion, garlic, and bell pepper to the pot. Sauté for about 5 minutes, or until the vegetables are softened.
Stir in the chili powder, cumin, paprika, salt, and black pepper. Cook for 1-2 minutes until the spices are fragrant.
Pour in the diced tomatoes (with juice), drained kidney beans, drained black beans, and beef broth. Stir to combine all ingredients.
Bring the chili to a simmer. Reduce the heat to low, cover, and let it cook for about 30 minutes, stirring occasionally to prevent sticking.
Taste and adjust seasoning if needed. If you prefer a thicker chili, you can let it simmer uncovered for an additional 10-15 minutes.
Serve hot with optional toppings like shredded cheese, sour cream, or chopped green onions.