Place the beef pieces in a skillet over medium heat and brown them on all sides for a few minutes. Transfer the beef to the slow cooker.
Add the mushrooms, onion, and garlic to the slow cooker. Pour in the beef broth, Worcestershire sauce, paprika, salt, and black pepper.
Cover and cook on low for 7 to 8 hours until the beef is tender.
About 15 minutes before serving, cook the egg noodles in a pot of boiling water according to package directions. Drain them well.
Stir the sour cream into the slow cooker until the sauce is smooth. Serve the beef mixture over the cooked egg noodles and sprinkle with chopped parsley.