Preheat oven to 350°F (180°C).
Pat the beef dry and sprinkle with a little salt and pepper. Heat the vegetable oil in a large pot over medium-high heat. Brown the flank steak on all sides and transfer to a plate.
Note: Do not discard the drippings.
Add the onion and peppers to the pot and cook, stirring and scraping up the browned bit from the bottom of the pot. Cook until onions are slightly tender and caramelized. Add the garlic and cook for 1 minute longer. Lower the heat to medium.
Add the tomato paste, cumin, oregano. Stir to combine. Cook, stirring and scraping for 1 minute.
Add the wine and bring to a simmer. Boil for about two minutes. Add the canned tomatoes and stock. Return the beef to the pot and nestle it beneath the onions and vegetables. Add the paprika, bay leaf, and parsley to the pot. Add more stock if necessary (only enough to just cover the ingredients). Cover the pot with a lid and transfer to the oven. Cook until beef is very tender for about 2 hours.
Remove the bay leaf. Stir in olives. Simmer until the juices have reduced enough to coat the beef in a glaze. Season with salt and pepper.
You may add fresh cilantro as a garnish. Serve with rice and black beans.