Freshly dug, true "new" potatoes are so creamy and flavorful they hardly need any additional ingredients to make them spectacular. Here we tumble them with a bit of butter, tangy yogurt, scallions and just-chopped fresh parsley. If new potatoes are not available, use any small red potatoes.
Bring 1 inch of water to a boil in a large saucepan fitted with a steamer basket. Add potatoes, cover and steam until very tender when pierced with a fork, 20 to 25 minutes. (Check the water level near the end of steaming to be sure the pan doesn't boil dry. Add more boiling water as needed.) Meanwhile, combine yogurt, scallions, parsley, butter, salt and pepper in a large bowl. Mix the cooked potatoes into the yogurt mixture, breaking them up with a fork until they crumble apart and lightly clump together.