Heat olive oil in a large pot or Dutch oven over medium-high heat. Add the beef cubes and brown them on all sides, about 5-7 minutes. Remove the beef from the pot and set aside.
In the same pot, add the diced onion and minced garlic. Sauté for 2-3 minutes until golden and fragrant.
Return the browned beef to the pot. Add carrots, celery, potato, green beans, diced tomatoes, and beef broth.
Stir in the dried thyme, dried basil, bay leaf, salt, and pepper.
Bring the soup to a boil, then reduce the heat to low. Cover the pot and let it simmer for about 1 hour, stirring occasionally.
After 1 hour, check the beef for tenderness and the vegetables for doneness. If the beef is tender, remove the bay leaf. Adjust seasoning with salt and pepper if needed.
Serve hot, garnished with chopped parsley.