German potato salad is widely believed to actually have originated in Germany, although it could have started in many countries it almost certainly began in Europe. It differs from American potato salad in that it is served warm and doesn’t contain mayonnaise or mustard. American potato salad is served cold and most likely originated from recipes brought to the U.S. by way of German and other European immigrants during the nineteenth century     A Japanese version is called potesara. It traditionally consists of mashed boiled potatoes, cucumber, onion, carrot, boiled eggs, and ham mixed with Kewpie mayonnaise, rice vinegar, and karashi mustard.       This potato salad is…