Prepare ingredients: Cube the beef, dice carrots and celery, chop the onion, and mince the garlic. Rinse barley if desired.

(Optional) Brown the beef in a hot skillet for 4–5 minutes to develop flavor and color. Transfer to the slow cooker.

Add the barley, beef broth, carrots, onion, celery, garlic, thyme, bay leaf, and a pinch of salt and pepper to the slow cooker.

Stir everything to combine. Cover the slow cooker.

Cook on low for 8 hours or on high for 4 hours, until the beef is tender and the barley is cooked through.

Remove and discard the bay leaf. Taste and adjust seasoning with salt and pepper. If the soup is too thick, stir in a bit of hot water or extra broth to reach your preferred consistency.

Serve hot with a sprinkle of fresh parsley.