Start by cutting the beef stew meat into bite-sized pieces and chopping all the vegetables.
Place the beef stew meat in the bottom of the crock put. Add the rinsed barley followed by the carrots, celery, onion, garlic and mushrooms.
Sprinkle the dried thyme, rosemary, salt and pepper over the ingredients. Add the bay leaf
Pour the diced tomatoes (with their juice) over the top, followed by the beef broth.
Cover the crockpot and cook on low for 7-8 hours or on high 4-5 hours, until the beef is tender and the barley is cooked through.
Once the soup is done, remove the bay leaf. Stir the soup to combine all the flavors. Taste and adjust seasoning if needed.