Heat a large pot over medium-high heat and add a splash of oil.
Add the beef stew meat, seasoning with salt and pepper, and brown on all sides.
Remove the meat and set aside. In the same pot, add onions, carrots, and celery.
Add the garlic and cook for an additional minute.
Return the browned beef to the pot, then add the broth, barley, bay leaf, and thyme.
Bring the soup to a boil, then reduce heat to low and simmer for at least an hour.
Taste and adjust seasoning if necessary. Remove the bay leaf before serving.