place flour, salt and pepper in shallow dish, dredge beef

heat large skillet over medium-high heat, add oil

cook beef until browned (7 minutes) stirring occasionally

transfer beef to crockpot

add onion and mushrooms to drippings in skillet and cook, stirring often, until tender (3 minutes) and add to crockpot

at the same time, combine broth, tomato paste and mustard

add broth mixture to skillet, stirring to loosen drippings from skillet

pour over beef in crockpot

cover and cook on low 3 hours

just before serving, stir in sour cream and sherry

serve over egg noodles