Rabo de toro estofado

Ingredients

• 2 kg oxtail, cut into sections at the joints
• 750 ml Pedro Ximénez or full-bodied red wine, Rioja or Ribera del Duero if not using PX
• 2 onions, roughly chopped
• 2 carrots, roughly chopped
• 4 garlic cloves, lightly crushed
• 2 bay leaves
• 1 tsp black peppercorns, whole
• 30 g dark chocolate, 85% cocoa or above, broken into pieces
• 3 tbsp olive oil, for browning
• 1 tsp salt, plus more to adjust

Method

1. 1
   Pat the oxtail sections completely dry. Season generously with salt. Heat the olive oil in a large heavy pot over high heat until it shimmers. Brown the oxtail in batches — each piece must lie flat and undisturbed — until every surface is deeply mahogany and the pot carries a heavy caramelised crust. Do not crowd the pot at any stage. The pieces are ready when they release cleanly and show a uniformly dark, not merely golden, exterior.
2. 2
   Remove the browned oxtail and set aside. Reduce the heat to medium. Add the onions, carrots, and garlic to the same pot and cook in the rendered fat, scraping up the caramelised fond, until the vegetables are softened and beginning to colour. They are ready when they smell sweet and the fond has been fully lifted from the base.
3. 3
   Return the oxtail to the pot. Pour in the wine — it should come at least two-thirds up the meat. Add the bay leaves and peppercorns. Bring to the point where small bubbles break the surface steadily, then reduce to the lowest heat that maintains a bare simmer. Cover and braise for 3–4 hours. The braise must never boil. The oxtail is done when the meat yields entirely to the pressure of a spoon and begins to loosen from the bone of its own weight.
4. 4
   Remove the pot from the heat and allow it to cool to room temperature. Transfer, uncovered, to the refrigerator and rest overnight. By morning the fat will have solidified on the surface in a pale, opaque layer. Lift and discard it entirely. The surface beneath should be a dark, trembling, almost set jelly.
5. 5
   Lift the oxtail pieces from the braising liquid and set aside. Pass the liquid and all solids through a fine-mesh sieve, pressing firmly on the vegetables to extract every drop of flavour. Return the strained sauce to the pot and bring to a simmer. Reduce, stirring occasionally, until the sauce coats the back of a spoon in a dense, dark, glossy film that does not run off quickly.
6. 6
   Add the dark chocolate to the reduced sauce over low heat and stir until fully melted and incorporated. Return the oxtail to the pot and warm through gently. The finished sauce should taste wine-rich, deep, and barely sweet — the chocolate rounds rather than sweetens. Adjust salt.