Step 1: Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat. Add ground beef and cook, breaking it up with a spoon, until browned and cooked through, about 5-7 minutes. Drain any excess fat.
Step 2: Add chopped onion and bell pepper to the pot. Cook until softened, about 5 minutes. Stir in minced garlic and cook for another minute until fragrant.
Step 3: Stir in chili powder, ground cumin, dried oregano, smoked paprika, and cayenne pepper (if using). Cook for 1 minute, stirring constantly, to toast the spices.
Step 4: Pour in crushed tomatoes, tomato sauce, kidney beans, pinto beans, beef broth, salt, and black pepper. Stir everything together.
Step 5: Bring the chili to a simmer, then reduce heat to low, cover, and let it simmer for at least 30-40 minutes, stirring occasionally, to allow the flavors to meld. For a richer flavor, simmer for 1-2 hours.
Step 6: Taste and adjust seasonings as needed. If the chili is too thick, add a little more beef broth or water. Serve hot with your favorite toppings!