Nachynka z kapusty (cabbage filling for varenyky)

1 lb Sauerkraut
      3 c  Fresh White Cabbage;
           -Shredded
      3 md Onions
    1/2 c  Oil; OR
    1/4 lb butter; 1 stick
      2 ts Freshly Ground Black Pepper;
           -Or To Taste
      1    Bouillon Cube
 
  Pour off the sauerkraut juice, reserving the juice, chop it up and set
  aside.  Saute the onions in the oil or butter until golden.  Add the
  drained, chopped sauerkaraut, cabbage, bouillon cube, and sauerkraut
  juice. Cook over low heat, uncovered, until the liquid evaporates,
  stirring often. Add the pepper, stir and cool.  Chop once or twice in
  the processor or run through a meat grinder.
  NOTE:  This stuffing is also excellent in Pyrizhky or crepes.  Keeps
  well in the refrigerator.