Hot German Sweet and Sour Beef Heart

Cut heart in half and trim; cover with water. Add 1 teaspoon salt, onion, bay leaf and celery. Cook about 1 hour; cool and remove heart and vegetables (discard vegetables). Trim off waste and cut into approximately 1/2-inch cubes. Meanwhile make a roux of butter and flour; cook slowly until medium brown color, stirring constantly. Add hot broth, slowly, stirring constantly until light to medium thick consistency is reached (you may have broth left over). Add sugar and vinegar. Add cubed heart and simmer 15 to 20 minutes. Adjust salt, vinegar and sugar to taste. Serve over boiled or mashed potatoes.