Quarter the potatoes and place in a large stockpot with cold water to cover. Bring to a boil, then reduce the heat to medium-low. Simmer about 25 minutes until the potatoes are fork tender. Drain.
In a large bowl, whisk the yogurt, olive oil, vinegar, rosemary, salt, and black pepper, until smooth. Fold in the potatoes and peppadew chilies. Cover and refrigerate at least one hour before serving.
Nutritional stats per serving (1/4 pound): 175 calories, 5 g protein, 28 g carbohydrates, 4 g fat (1g saturated), 3 mg cholesterol, 0 g fiber, 375 mg sodium