Preheat oven to 375°. Generously season roast with salt and pepper. Place roast in your roasting pan with the lid on and place in the oven for 20 minutes. After 20 minutes turn the heat down to 325° and roast for 2-3 hours, basting several times.
To check if your roast is ready, use a fork to see if it easily shreds. If it does. it's ready if not give it another half hour.
Remove roast and allow to rest. Bring the water, along with bay leaf and thyme to a rolling boil in a large pot, and add a generous amount of salt as well as the bouillon. Once it is boiling, add egg noodles and allow to cook for a minute under what the package says.
While pasta cooks, shred beef. When your pasta is done cooking, you can remove some liquid from your pot if you feel it has too much liquid. Typically, I don't do this, I usually like the amount of liquid that is remaining.
Add in your shredded beef, and remove the thyme and bay leaf. Make a slurry with your cornstarch and cold water, then using a spoon or whisk, move noodles, and beef away and whisk in your cornstarch, then, using a spoon, give it several good stirs to incorporate the cornstarch throughout the pot.
Season with additional salt and pepper as needed.