German potato salad (Kartoffelsalat)

In southern Germany this coarse cut potato side dish is served with vinegar and oil. In northern Germany mayo is added, but how did this recipe become widespread when potatoes were not part of the old German diet.
Potatoes (Kartoffel) got to Germany by a long route first from the Spanish from South America to Spain, and then they slowly spread throughout Europe. The Spanish first thought they were truffles! Maybe because they were dug from the earth like truffles are. The Italians were the first to try cultivating the potato,but with little luck. The word Kartoffel comes from the Italian word Tartufolo (truffles). Since the leaves were poisonous the potato got a bad reputation as something to avoid.
Potatoes also got the reputation for causing lustful thoughts, so many avoided these "fruits of the devil" even if they were hungry! The first cultivated potatoes were not very good either. They were very small and sometimes bitter. It took some cross breading to get the potato as we know it today. In it's modern fashion it is only about 250 years old.The first potatoes were planted in Germany in the mid 1500's but It became something only the peasants grew on their land and ate as cheap sustenance for many years.

Ingredients
Four to five potatoes (you may use one pound of new potatoes leaving skin) boil potatoes till medium soft.
One small yellow or white onion
One small red onion
Eight to ten strips of bacon cooked and cut into pieces.
Kielbasa sausage, one pound
1/4 cup of chop green onion
Salt and pepper to taste
One tsp of mustard sead
Olive oil
Malt vinager if desired, about one TBSP

Boil potatoes, till medium soft, then cut into medium size pieces. Place into large open pan diced onions oli and sausage, when golden add the potatoes. Mix well and season. Cook till golden brown. Add then bacon and stir . Finally add if desired the vinager and green onion. Serve hot as is or with some favorite cheese .