Season the beef chuck roast cubes with 1 teaspoon kosher salt and 1/2 teaspoon black pepper, tossing to coat all sides evenly.
Heat the olive oil in a large skillet over medium-high heat. When hot, add half of the seasoned beef cubes in a single layer and sear for 2 to 3 minutes per side until browned. Transfer the browned beef to the crockpot and repeat with the remaining beef cubes.
In the same skillet, add the finely chopped yellow onion and cook over medium heat for 3 to 4 minutes, stirring often, until softened and lightly golden. Add the minced garlic and cook for 30 seconds until fragrant, then remove the skillet from the heat.
Pour about 1/2 cup of the low-sodium beef broth into the skillet, scraping up any browned bits from the bottom with a wooden spoon. Transfer the onion, garlic, and deglazed broth mixture into the crockpot over the seared beef.
Add the remaining beef broth, Worcestershire sauce, dried thyme, dried parsley, paprika, onion powder, garlic powder, 1/2 teaspoon additional salt, and 1/4 teaspoon additional black pepper to the crockpot. Stir gently to combine all the ingredients.
Cover the crockpot with the lid and cook on LOW for 7 to 8 hours, or on HIGH for 4 to 5 hours, until the beef is very tender and easily breaks apart with a fork.
About 30 minutes before serving, whisk the cold water and all-purpose flour together in a small bowl until completely smooth with no lumps to create a slurry.
Uncover the crockpot and slowly pour in the flour slurry while stirring the beef mixture. Stir well to distribute the slurry evenly, then cover and cook on HIGH for 15 to 20 minutes, or until the sauce has thickened into a rich gravy.
Once the gravy has thickened, stir the uncooked wide egg noodles directly into the crockpot, making sure they are mostly submerged in the liquid. Cover and cook on HIGH for 10 to 15 minutes, stirring once halfway through, until the noodles are tender but not mushy.
Turn off the heat. Add the sour cream to the crockpot and gently fold it into the beef and noodles until the sauce becomes creamy and well blended.
Sprinkle the chopped fresh parsley over the top, give the beef and noodles a final gentle stir, and let the dish rest for 5 minutes before serving to allow the flavors to settle and the sauce to thicken slightly.