from the Stephen Taber

2 pounds potatoes
1 medium onion
mayonnaise, salt, pepper and paprika to taste
1/3 cup vinegar
2 tablespoons oil

Cook potatoes whole, in jackets, until done but still firm. Peel and slice thinly. Marinate in oil and vinegar for several hours in the refrigerator. Just before serving add diced onion, seasonings and mayonnaise. Sprinkle with paprika.