Set the Instant Pot to "Sauté" mode and heat the olive oil. Add diced onion and cook for 2-3 minutes until softened. Stir in the garlic and bell pepper, cooking for an additional minute.
Brown the beef
Add the ground beef to the pot. Break it up with a spoon and cook until browned, about 5 minutes. Drain excess fat if necessary.
Bloom the spices
Stir in chili powder, smoked paprika, cumin, oregano, salt, black pepper, and cayenne (if using). Let the spices cook for 1-2 minutes to release their flavors.
Deglaze the pot
Stir in the tomato paste and beef broth, scraping the bottom of the pot to lift any browned bits (they add flavor!).
Add the remaining ingredients
Pour in the diced tomatoes, tomato sauce, kidney beans, and black beans. Stir well to combine.
Cook under pressure
Secure the Instant Pot lid and set the valve to "Sealing." Cook on "Manual" or "Pressure Cook" mode for 15 minutes.
Quick release and stir
After cooking, perform a quick release of pressure. Carefully open the lid and give the chili a good stir. Adjust seasoning as needed.
Serve and garnish
Ladle the chili into bowls and add your favorite toppings. Serve hot and enjoy!