Little fingerling potatoes are fantastic in potato salads, in part because their skin-to-flesh ratio is much smaller than big potatoes, so there’s more interesting textural difference in every bite. Like with any potato salad, one key to success is dressing the potatoes while they’re still hot so they fully absorb flavorings.
Place potatoes in a medium saucepan. Cover with water by 3 inches; bring to a boil. Reduce heat to medium-low; cook 20 minutes or until potatoes are tender. Drain well. Add hot potatoes to dressing; toss gently to coat. Add onion and chives; toss.