Combine 1/2 cup flour, salt pepper and dry mustard; toss with steak strips to coat thoroughly.
Place coated steak strips in crock pot; stir in onions rings and mushrooms. Add beef broth and wine; stir well.
Cover and cook on low setting for 8 to 10 hors. Before serving, combine sour cream with 1/4 cup flour stir into crock pot.
Serve stroganoff over hot buttered noodles, garnish with minced parsley.
Servings: 4 to 6