In a large pot, bring potatoes to a boil in salted water over high. Reduce to a simmer and cook until tender when pierced with a knife, 15 to 20 minutes. Drain and let cool completely. Cut potatoes into 1 1/2-inch pieces.
In a large bowl, combine mayonnaise,sour cream green onion, lemon juice, and spices. Add potatoes and toss to combine. Season with salt and pepper. To store, cover and refrigerate before serving for a even better taste.