Trim excess fat from meat.
Cut meat in thin strips.
Combine flour with salt, pepper, paprika and mustard.
Toss meat with seasoned flour.
Melt 1/3 of the butter in large heavy skillet.
Add garlic; saute until golden.
Saute onions for 5 to 6 minutes.
Saute meat strips until browned; add bouillon and onions.
Stir to dissolve browned bits in bottom of skillet.
Simmer, uncovered, 15 to 20 minutes, until meat is tender and mixture is thickened, stirring occasionally.
Add tomato ketchup or paste, worcestershire sauce and sour cream.
Serve over noodles or rice.
Sprinkle top with chives or parsley, if desired.