Wash the scallions thoroughly and cut them in half. Reserve the green part for boiling the meat, and the white part for the sofrito. Peel the yellow onion and dice it. Peel the garlic and crush it in a mortar.
Wash the sweet mild chilies, cut 3 of them in half and remove the seeds, then dice them. Repeat the same process with the bell pepper; however, the bell pepper pieces should be larger. Save one whole sweet mild chili pepper for boiling the meat.
Pour two liters of water into a pot, add a teaspoon of salt, the green part of the scallions, the remaining sweet mild chili pepper, the bay leaves, and the meat. We used a pressure cooker, and after one hour of cooking over medium heat, the meat will be tender enough to shred. If you don't have a pressure cooker, cook the meat over medium heat for a minimum of two hours.
While the meat is cooking, make the sofrito. Heat the oil in a medium skillet or medium sized pot until hot, and add the diced yellow onion, the white part of the scallions, and the crushed garlic. Cook for three to five minutes until the onions are translucent.
Add the chopped sweet chilies and bell pepper. Season with celery salt and pepper. Stir well. Continue cooking for another five minutes.
Add the Worcestershire sauce, the tomato passata purée, and the wine. Stir. Cook for another five minutes, then turn off the heat.
Remove the meat from the pot and let it rest until you can handle it with your hands. While this is happening, let the broth from the meat continue to reduce and cook down; you will use 1 cup of this concentrated beef stock for the final dish.
Place the meat on a suitable surface, remove any excess fat, and then shred it with your hands or with a fork.
Finally, add the shredded beef to the pot with the sofrito sauce and the concentrated beef stock. Stir well and cook covered on low heat for another 10-15 minutes.
You can serve the ropa vieja shredded beef with white rice and fried plantains or your preferred side dishes.