01 - Heat olive oil in a large Dutch oven or heavy-bottomed pot over medium-high heat.
02 - Add beef cubes in batches and sear until browned on all sides. Remove and set aside.
03 - Reduce heat to medium. Add onion, carrots, and celery; sauté for 5 to 7 minutes until softened.
04 - Stir in minced garlic and cook for 1 minute until fragrant.
05 - Return beef to the pot then add diced tomatoes, barley, beef broth, water, bay leaves, thyme, rosemary, salt, and black pepper. Stir well.
06 - Bring to a boil, reduce heat to low, cover, and simmer for 1½ to 2 hours, stirring occasionally, until beef and barley are tender.
07 - Discard bay leaves and adjust seasoning as needed.
08 - Ladle stew into bowls and garnish with chopped fresh parsley if desired.