In a large pot, heat oil over medium heat.
Add the cubed beef and brown on all sides.
Remove the beef and set aside.
In the same pot, sauté onion, carrots, and celery until softened.
Stir in garlic and cook for 1 minute.
Return the browned beef to the pot.
Add beef broth, barley, thyme, and bay leaf.
Bring to a boil, then reduce heat and simmer for about 1 hour.
Season with salt and pepper to taste before serving.