1. In a large pot, over medium-high heat, warm olive oil. Add beef cubes and cook for about 8 minutes; stirring occasionally until browned on all sides.
2. Stir in beef broth, water, onion, celery, carrots, oregano, black pepper, garlic, barley and bay leaf. Bring to a boil. Then reduce heat to low, cover and simmer for 45 minutes.
3. Stir in green beans, tomatoes and peas. Simmer, covered, until meat and vegetables are tender, about 15 more minutes. Remove bay leaf.
4. Ladle a portion (about 2 cups) of soup into each bowl. Serve and enjoy!