In a large pot or Dutch oven, brown the ground beef over medium heat, breaking it up with a wooden spoon until fully cooked (about 5-7 minutes). Drain excess fat if necessary.
Add the diced onion, garlic, and bell pepper to the pot, cooking until softened (approximately 5 minutes).
Stir in the chili powder, cumin, paprika, salt, and black pepper, cooking for another 1-2 minutes until fragrant.
Add in the drained kidney beans, black beans, crushed tomatoes, tomato paste, and beef broth. Stir well to combine all ingredients.
Bring the mixture to a simmer, then reduce heat to low. Cover and let it cook for about 30 minutes, stirring occasionally.
Taste and adjust seasoning if needed. Serve hot with your choice of toppings.
For a spicier chili, consider adding fresh chopped jalapeños or red pepper flakes during the cooking process.
If you prefer a vegetarian version, substitute the ground beef with lentils or textured vegetable protein (TVP) and use vegetable broth instead.