-
1
Place the flank steak in a pot with the halved onion, bay leaf, and cumin. Cover with cold water by at least 5 cm. Bring to a boil, skim the grey foam, then reduce to a steady simmer. Braise, partially covered, for a minimum of 2 hours — the steak is ready when its fibres separate from one another with no resistance when pressed with two forks.
-
2
Lift the steak onto a board and reserve 250 ml of the braising liquid. When the meat is cool enough to handle, shred it along the grain into long, coarse strands — the parallel muscle fibres of flank or skirt will separate naturally. Discard any sinew.
-
3
Heat the oil in a wide, heavy pan over medium heat. Add the onion and both peppers and cook, stirring regularly, until they are completely soft and beginning to colour. Add the garlic and cumin and continue cooking until the whole mass has darkened to a deep, caramelised, rust-coloured paste — this is where the dish lives or dies: pale sofrito produces a raw-tasting sauce and the transformation to ropa vieja cannot happen.
-
4
Add the crushed tomatoes to the sofrito. Cook over medium heat, stirring and pressing the tomatoes into the paste, until the mixture has reduced and the oil begins to separate at the edges — a sign that the water has cooked off and the base is concentrated.
-
5
Add the shredded beef to the sofrito. Pour in the reserved braising liquid gradually, stirring so it binds the tomato and pepper to the beef strands. Raise the heat to medium-high and sauté, turning the beef frequently, until each strand is coated in a glossy, clinging sauce and the beef itself shows visible colour from the pan — the Maillard development that separates ropa vieja from plain braised beef.
-
6
Add the olives and capers. Fold through gently. Taste the sauce now, before reaching for salt — the olive brine and capers contribute significant salinity and may render additional seasoning unnecessary. Adjust if required.