Season the beef with salt and pepper. Add the beef in batches to avoid overcrowding and sear on all sides until browned.
Pour in the beef broth, Worcestershire sauce, and Dijon mustard, scraping the bottom of the pot to deglaze.
Add the egg noodles, making sure they are fully submerged in the liquid. Reseal the lid and cook on High Pressure for 3 minutes, then manually release the pressure.
Stir in the sour cream, adding more if you prefer a creamier texture, and adjust salt and pepper to taste. Garnish with chopped parsley if desired.