PLACE meat, mushrooms, onions and garlic in slow cooker. Add broth, paprika and salt. Cover with lid. Cook on LOW 7 to 8 hours (or on HIGH 5 hours).
MIX sour cream, flour and mustard. Stir into ingredients in slow cooker until well blended. Cook, covered, on LOW 15 min. Meanwhile, cook noodles as directed on package.
DRAIN noodles; place in large serving bowl. Add meat mixture; mix lightly. Sprinkle with parsley.