Lightly grease slow cooker, and line with dried beef. Place 2 to 3 chicken breasts in the slow cooker. In a mixing bowl, stir together sour cream, soup, and flour; pour 1/2 of mixture over chicken. Layer with the dried beef and chicken breasts, and pour in the remaining sour cream mixture. Top with the remaining dried beef.
Cook in slow cooker on LOW for 8 hours, or on HIGH for 4 hours.