Season beef with salt and pepper. Place 2 teaspoons oil in the bottom of a pot. When hot, work in batches to brown the beef. Place on a plate once browned.
Add remaining 2 teaspoons oil to pot and sauté the onions and celery over medium heat until softened. Add the garlic and cook 30 seconds.
Add in the browned beef, carrots, tomatoes, potatoes, barley, broth, salt, pepper, thyme, and bay leaf. Bring to a boil, cover, reduce heat to low and let simmer 60-90 minutes or until beef is tender.
Add the green beans and simmer 4 more minutes. Remove bay leaf and thyme sprigs. Serve garnished with parsley and a side of hearty bread.