Season the beef with 1 1/2 teaspoons salt and the pepper and blot it dry.
Heat the oil in a skillet over medium-high heat and brown the beef in 2 batches for 4 minutes per batch.
Transfer the beef to a 6-quart crockpot and add the onion, carrots, celery, garlic, broth, barley, Worcestershire, thyme, bay leaves and remaining salt.
Cover and cook on low for 7 to 8 hours until the beef is fork-tender and at least 145°F and the barley is soft.
Discard the bay leaves and add up to 1 cup hot water if the barley has made the soup thicker than a loose stew.