Beef Barley Soup (Slow Cooker)

Place beef stew meat, pearl barley, onion, carrots, celery, and garlic in a slow cooker.
Add beef broth, diced tomatoes, thyme, and rosemary.
Cover and cook on low for 8-10 hours or on high for 4-5 hours, until the meat is tender and the barley is cooked through.
Season with salt and black pepper to taste.
Serve hot, garnished with chopped fresh parsley.