Pat beef cubes dry with paper towels and season with salt and pepper.
Heat vegetable oil in a large pot or Dutch oven over medium-high heat.
Sear beef in batches until browned on all sides, then remove and set aside.
In the same pot, sauté diced onion until translucent, about 5 minutes.
Add minced garlic and cook for 1 minute until fragrant.
Return beef to the pot and stir in beef broth, Worcestershire sauce, and dried thyme.
Bring to a boil, then reduce heat to low, cover, and simmer for 1 hour 30 minutes or until beef is fork-tender.
In a small bowl, whisk cornstarch and cold water to create a slurry.
Stir the slurry into the pot and simmer for 3-5 minutes until the gravy has thickened.