Remove the ribs from the sorrel leaves. Cut the sorrel leaves fine and put through a meat-grinder. Cook in the hot butter until done. Sprinkle with the flour, brown a little, dilute with water, and boil until thick. Add a big amount of the sour cream and boil again for 3—5 minutes. If the sorrel leaves are still too sour, pour boiling water over them, then mince and cook.