Heat the oil over medium heat in a large pot, add the onions, garlic, scallions, bell pepper, cumin and achiote. Cook for about 5 minutes, stirring often.
Add the beef broth to the pot and bring to a boil. Reduce the heat to medium and cook for 20 minutes.
Add the patacones and cook over low heat for about 10-15 minutes, be very careful not to stir the soup, to avoid breaking the patacones.