In large skillet on low heat, MELT butter; ADD beef; COOK, STIRRING, until just done.

DISSOLVE bouillon cube in hot water; DIVIDE broth in half, reserving one half for later.

MIX together remaining broth, catsup, salt and garlic; ADD to skillet.

HEAT to boiling, STIRRING; REDUCE heat to low; COVER; SIMMER until beef is tender, about ten minutes.

Meanwhile, start COOKING noodles according to package directions.

STIR mushrooms and onion into beef mixture; COVER; SIMMER until onion is tender, about five minutes.

MIX together reserved broth and flour; gradually STIR into beef mixture; HEAT until boiling, STIRRING constantly; BOIL and STIR one minute.

STIR sour cream into beef mixture; HEAT through.