Soaking the red onion in cold water mellows its strong flavor.

　　

Ingredients

Makes 4 to 6 servings

　　2 pounds small yellow-fleshed potatoes such as Yukon Gold

　　1 small red onion, finely chopped (1/3 cup)

　　2 tablespoons fresh lemon juice

　　3/4 teaspoon salt

　　1/2 cup sour cream

　　1/3 cup mayonnaise

　　1/4 cup chopped fresh dill

　　

Step 1

Cover potatoes with salted cold water by 1 inch and bring to a boil, then reduce heat and simmer, uncovered, until potatoes are tender, 15 to 20 minutes. Reserve 1/4 cup cooking water, then drain potatoes in a colander.

　　

Step 2

While potatoes are boiling, soak onion in cold water 15 minutes, then drain in a sieve and pat dry.

　　

Step 3

When potatoes are just cool enough to handle, peel and quarter, then toss with lemon juice and salt in a large bowl.

　　

Step 4

Whisk together onion, sour cream, mayonnaise, dill, and reserved cooking water in a bowl until blended. Whisk in salt and pepper to taste, then add to potatoes and toss to coat. Serve warm.