**Prepare the Beef:** Season the beef generously with salt and pepper.
**Optional Searing:** Heat olive oil in a skillet over medium-high heat. Sear the beef on all sides until browned, about 3–4 minutes per side. This step adds extra flavor but can be skipped for convenience.
**Load the Slow Cooker:** Place the beef in the slow cooker. Add beef broth, onion soup mix, garlic powder, and thyme. Stir to combine.
**Cook:** Cover and cook on low for 8–10 hours or on high for 4–5 hours, until the beef is tender and easily shredded.
**Shred the Beef:** Use tongs or two forks to shred the cooked beef directly in the slow cooker.
**Cook the Noodles:** About 20–30 minutes before serving, add the egg noodles to the slow cooker. Stir well to submerge them in the broth, cover, and cook on high until tender.
**Optional Creaminess:** Stir in heavy cream if a creamier sauce is desired.
**Serve:** Garnish with fresh parsley and serve warm.