Place sauerkraut in saucepan. Add water just to cover. Mix sugar and flour together and add to sauerkraut and stir. Add as much caraway seed as desired--I usually use about 1/2 teaspoon. Simmer, covered, for about 20 minutes. Add fat and heat through. Serve.
Note: When I make this when we have duck, I drain off the duck grease and use that for the fat.