Stroganoff Soup

Prep :  15 minutes        Cook : 40  minutes   Makes 6 servings

1/2            pound boneless beef sirloin steak or beef tenderloin , cut into thin strips
1/2            cup chopped onion
1               tablespoon butter
2               cups water
1-1/2         cups milk
1/4            cup tomato paste
2               teaspoons beef bouillon granules
1               can (8 ounces) mushroom stems and pieces , drained
1               teaspoon salt
1/8            teaspoon pepper
1               can (12 ounces) evaporated milk
1/3            cup all purpose flour
2               cups cooked wide egg noodles
1/2             cup sour cream

1 .        In a 3-quart saucepan , cook beef  and onion in butter  over medium heat  until meat is browned . Stir in the  water , milk , tomato paste and  bouillon . Add mushrooms  , salt and pepper  ; bring to a boil  . Reduce heat  ; cover and simmer  for 20 to 30 minutes  or until meat is tender .
2 .        Combine evaporated milk and flour until smooth . Gradually add to soup . Bring to a boil ; cook  and stir 2 minutes  until thickened . Add noodles  ; cook until heated  through . Remove  from the heat ; stir in sour cream .