https://www.youtube.com/watch?v=f0JoW1ME4vw Serves: 10 | Serving size: ½ cup  Ingredients 2.5 lbs gold, red, or white potatoes ½ stick or 2 oz. unsalted butter, softened ½ cup or 4 oz. plain low-fat yogurt 2 tablespoons 1% milk, or more to adjust for desired texture *Optional: 1 tablespoon salt, used in boiling water *Optional: Fresh herbs or