01 - Heat vegetable oil in a large Dutch oven over medium-high heat. Add beef cubes in batches, browning on all sides. Transfer browned beef to a plate and set aside.
02 - In the same pot, add chopped onion, carrots, parsnips, and celery. Sauté for 5 minutes, stirring occasionally, until softened.
03 - Add garlic and cook for 1 minute until fragrant.
04 - Return browned beef to the pot. Add potatoes, barley, beef broth, water, bay leaves, thyme, salt, and pepper. Stir well to combine.
05 - Bring stew to a boil, then reduce heat to low. Cover and simmer for 2 hours, stirring occasionally, until beef and barley are tender.
06 - Remove and discard bay leaves. Taste and adjust seasoning with additional salt and pepper if needed.
07 - Ladle stew into bowls and garnish with chopped fresh parsley.