Ingredients

• 2 pounds fingerling potatoes, cut into large chunks
• 1 (8 ounce) container lowfat plain yogurt
• ¼ cup sour cream
• 1 lemon, zested and juiced
• 1 tablespoon coarse-grained mustard, or more to taste
• salt and ground black pepper to taste
• 2 cups torn arugula leaves