Fiery jalapeno adds a nice bite to the creamy potatoes and sweet corn; adjust the amount to suit your taste.
Place potatoes in a large pot of salted water and bring to a boil. Reduce heat and simmer for 20 minutes, or until tender. Remove from heat and drain. Let cool. Break potatoes into chunks with your fingers, or break them up with a wooden spoon.
Meanwhile, bring a small saucepan of water to a boil. Add corn and blanch until tender and bright yellow, about 3 minutes. Drain and let cool.
In a small bowl, combine yogurt and sour cream. Stir in lemon or lime juice, all but 2 tablespoons of the chives, and the jalapeno, and season to taste with salt and pepper.
In a large serving bowl, combine potatoes and corn, reserving some corn for garnish. Toss with dressing, and garnish with remaining corn and chives.