Using a sharp chef's knife, cut 2 lbs of chuck roast into ½-inch cubes. Pat them dry using a sheet of paper towel.
Season the cubed beef with 1 teaspoon kosher salt and ½ teaspoon of black pepper on all sides. Set aside.
Heat two tablespoons of olive oil in the Dutch oven over medium-high heat until it shimmers.
Add the beef cubes and brown them on all sides for about 6-7 minutes, about a minute or two per side. Transfer them onto a plate, cover it with aluminum foil, and set it aside. Do not wash the pot.
Add 3 cups chopped onion, 1 ½ cups of carrots, and 1 cup celery to the pot and cook on medium-high heat, until softened, stirring frequently, for about 10 minutes.
Add the 4 minced cloves of garlic and cook for 30 seconds.
Add 3 tablespoons of tomato paste and cook, stirring constantly for about a minute or so. Season with 1 teaspoon of kosher salt and ½ teaspoon of black pepper.
Stir in ½ cup of red wine and scrape any brown “bits” at the bottom of the pot using a wooden spoon.
Add the browned beef (with all the juices), 7 cups of beef broth, one 14-ounce can of diced tomatoes, and 3-4 sprigs of fresh thyme. Give it a stir, place the lid ajar, and bring it to a boil. Then, turn the heat down to medium-low and let it simmer for 30-45 minutes or until your meat is fully cooked and tender.
Next, stir in 1 cup pearl barley and 1 tablespoon of Worcestershire sauce.
Let it simmer, with the lid ajar, for 45-55 minutes, keeping a close eye on it and stirring occasionally, until the pearl barley is tender but has a slight “bite”.
Turn the heat off, remove the thyme bundle, and stir in 2 tablespoons of apple cider vinegar if using. Taste for seasoning and add more if necessary.
Add ½ cup of chopped fresh parsley and serve right away.