In a large pot or Dutch oven, heat the vegetable oil over medium-high heat.
Add the beef cubes in batches (do not overcrowd) and brown them on all sides. Remove the browned beef and set it aside.
In the same pot, add the chopped onions and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional minute until fragrant.
Return the browned beef to the pot. Add the beef broth, carrots, potatoes, celery, thyme, salt, pepper, bay leaf, tomato paste, and Worcestershire sauce.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 1.5 to 2 hours, stirring occasionally, until the beef is tender and the flavors meld together.
Adjust seasoning as needed and remove the bay leaf before serving.
Serve hot, garnished with fresh parsley if desired.