01 - Heat olive oil in a large Dutch oven over medium-high heat. Add beef cubes and brown evenly on all sides, about 5 to 7 minutes. Remove and set aside.
02 - In the same pot, add diced onion, carrots, celery, and mushrooms. Cook, stirring occasionally, until vegetables begin to soften, approximately 5 minutes.
03 - Stir in minced garlic and sauté for 1 minute until fragrant.
04 - Return beef to the pot. Add diced tomatoes with their juice, beef broth, water, pearl barley, diced potato, bay leaves, dried thyme, dried parsley, salt, and black pepper. Stir to incorporate.
05 - Bring the mixture to a boil, then reduce heat to low. Cover and simmer gently for 1 hour, stirring occasionally.
06 - Uncover and continue simmering for an additional 20 to 30 minutes, until beef and barley are tender and the liquid has thickened slightly. Adjust seasoning as needed.
07 - Remove bay leaves. Serve hot with optional fresh parsley garnish.