Step 1

In a large pot of boiling water over medium-high heat, cook potatoes 20 to 25 minutes, or until fork-tender. Drain and let cool.

Step 2

In a large bowl, whisk together yogurt, mayonnaise, mustard, vinegar, garlic powder, salt, and pepper.

Step 3

Cut potatoes into 1-inch chunks, add to dressing along with remaining ingredients, and mix until well combined. Cover and refrigerate until chilled.