You should start preparing the meal the previous day, by using a sharp knife and cut small openings in the meat. Insert pieces of garlic, bacon in it.
Transfer the beef in a large dish pour some vinegar to cover it and leave it overnight in the refrigerator.
The next day, remove the meat from the vinegar and drain it, you can use paper towels to soak as much liquid as possible.
Remove from the meat the garlic, bacon and and keep them in a small bowl for later.
Turn the stove to a medium high temperature and place a large saucepan with olive oil.
Place the meat in the saucepan, dust with flour and cook on medium high heat and about 8 to 10 minutes by turning regularly until brown on all sides.
Remove the meat from the saucepan and transfer it into a roasting dish. Season the beef with salt and pepper, olive oil, lard, onions, celery root and carrots then cover it with aluminum foil and roast for 45 minutes.
You can use same saucepan with the oil and fry the onion, garlic and bacon for a few minutes, stir constantly.
Return the meat to the pot, add broth and cook for about 6 to 8 minutes.
Return the meat to the pot, pour red and dessert wine, add the tomato paste, and cook covered on low heat for 3 hours.
After 1.5h add the bay leaf and prunes.
Check with a fork if the meat is tender, then transfer it to cutting board and and cut into thick slices.
The vegetables and sauce that have left transfer it and puree it into a blender.
You can serve with potato gnocchi and garnish with parsley.