Season beef with salt and pepper. Brown in oil in a hot skillet if desired.
Add beef to the slow cooker with beef broth, cream of mushroom soup, onion soup mix, Worcestershire sauce, and garlic powder.
Cover and cook on Low for 7 to 8 hours, until beef is very tender.
Remove beef, shred or chop it, and return it to the slow cooker.
Stir in frozen egg noodles.
Cover and cook on High for 30 to 45 minutes, stirring occasionally, until noodles are tender.
If the sauce is too thin, stir in a cornstarch slurry and cook a few minutes more.
Taste and adjust seasoning before serving.
Garnish with parsley if desired.
Notes
Stir the noodles a few times near the end so they cook evenly and do not clump. Keep some extra broth nearby because noodles continue to absorb liquid as they sit. Leftovers thicken in the refrigerator; reheat with a splash of broth. Browning the beef first adds flavor but the recipe still works if you need to skip that step.
Keyword crock pot beef and noodles, slow cooker beef and noodles