Heat the olive oil in a large pot over medium heat. Add the onion and garlic and cook until softened, about 5 minutes. Add the bell peppers and jalapeno pepper (if using) and cook for another 5 minutes.
Add the black beans, kidney beans, tomatoes with green chilies, tomato sauce, chili powder, cumin, salt and pepper. Stir to combine.
Bring to a boil then reduce heat to low. Simmer for 30 minutes or until everything is heated through.