- 1/2 cup mayonnaise
- 1/3 cup sour cream
- 3 tablespoons bottled white horseradish (not drained)
- 1 tablespoon white-wine vinegar
- 1 teaspoon sugar
- 3/4 teaspoon salt
- 1/2 teaspoon black pepper
- 1/3 cup chopped fresh chives
- 3 pounds cooked small (2-inch) boiling potatoes, cooled to room temperature and quartered
- Whisk together mayonnaise, sour cream, horseradish, vinegar, sugar, salt, and pepper in a large bowl until smooth. Add chives and potatoes and stir to coat.