Pat the beef chunks dry with paper towels, then season generously with salt and black pepper. Toss the beef in flour until evenly coated.
Heat olive oil in a large Dutch oven over medium-high heat. Working in batches, brown the beef on all sides for about 5-7 minutes. Remove beef and set aside.
In the same pot, add the diced onion and cook for 3-4 minutes until softened. Stir in the garlic and tomato paste, cooking for 1 minute until fragrant.
Pour in a splash of beef broth to deglaze the pot, scraping up any browned bits from the bottom.
Return the beef to the pot. Pour in the remaining beef broth and Worcestershire sauce. Add the fresh thyme. Bring to a boil, then reduce heat to low, cover, and simmer for 1 hour.
Stir in the baby potatoes and carrots. Cover and continue to simmer for an additional 45-60 minutes, or until the beef and vegetables are fork-tender.
If a thicker stew is desired, stir in a cornstarch slurry or a tablespoon of potato flakes during the last 5 minutes of cooking. Serve hot.