Sear the beef in batches: Season the beef chunks with salt and pepper, then coat them in flour. Brown the beef in a large stockpot over medium-high heat, working in batches to avoid overcrowding. Transfer the browned beef to a clean plate as you go.
Sauté the aromatics: Add the oil to the stockpot, if needed. Sauté the onion for 4-5 minutes, or until softened. Stir in the garlic and cook for 1 minute. Add the cooked beef, thyme, bay leaf, Worcestershire sauce, and 6 cups of water to the pot. Stir to combine.
Slow cook the beef: Bring to a low simmer, and add bouillon. Reduce heat to maintain a gentle simmer, cover the pot, and cook for 2.5 hours, or until the beef is tender enough to shred easily with a fork.
Shred the beef: Carefully transfer the cooked beef to a clean plate and shred it into bite-sized pieces using two forks. Discard the bay leaf and thyme sprigs.
Cook the noodles: Add the remaining 2 cups of water/stock to the pot and bring to a boil over high heat. Add the egg noodles and cook, stirring occasionally, until al dente.
I usually like to create a slurry of cornstarch and cold water and thicken the gravy up a bit before adding the beef in. Use more or less for the desired thickness.
Combine and serve: Remove the pan from the heat and stir in the shredded beef. Season with salt and pepper to taste.
Serve immediately, garnished with black pepper.