Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion, bell pepper, and garlic. Sauté until the vegetables are softened and the onion is translucent, about 5 minutes.
Add the ground beef to the pot. Cook until browned, breaking it apart with a spoon, about 7-10 minutes.
Stir in the chili powder, cumin, paprika, salt, and black pepper. Cook for an additional 2 minutes to toast the spices.
Add the diced tomatoes (with their juice), kidney beans, black beans, and beef broth to the pot. Stir to combine all ingredients.
Bring the mixture to a gentle boil, then reduce the heat to low. Cover and let it simmer for about 30 minutes, stirring occasionally to prevent sticking.
Taste and adjust seasoning if necessary. If desired, let it simmer longer for deeper flavors.
Serve hot, topped with your favorite toppings like shredded cheese, sour cream, or chopped green onions.