By J. Kenji López-Alt

A classic side dish for homemade lunch boxes or bento picnics, a Japanese potato salad is made with boiled russet potatoes, vegetables, boiled eggs and, often, ham, all seasoned with rice vinegar and tangy Japanese Kewpie mayonnaise. The potatoes in Japanese potato salad are typically roughly mashed, but you can dice them if you prefer a heartier texture. Salting the cucumber in advance helps it retain some crunch when you mix it into the salad, while adding vinegar to the potatoes while they’re still hot helps them absorb more flavor.

Note: My family makes this dish with Yukon gold potatoes, carrots, a salted, drained, and squeezed out cucumber, a thinly sliced raw apple, some chopped white onion, and sometimes, a thinly sliced Japanese fish cake (a processed seafood product). The Kewpie mayonnaise definitely adds an authentic flavor.

INGREDIENTS

Yield: 4 to 6 servings

  • 1 pound russet potatoes (about 2 whole large potatoes), peeled and cut into large chunks
  • Salt
  • 2 eggs
  • 1 tablespoon rice vinegar, plus more to taste
  • 2 teaspoons sugar
  • 1 small Japanese or Persian cucumber, or ½ an English cucumber (about 4 ounces), quartered lengthwise, seeds removed and discarded, and thinly sliced
  • 1 small carrot (2 to 3 ounces), quartered lengthwise and thinly sliced (The carrot, just thinly sliced, can be cooked with the potatoes.)
  • ½ cup thawed frozen corn kernels or briefly boiled fresh corn kernels (optional)
  • ¼ cup chopped radish (about 2 radishes; optional)
  • 2 scallions, thinly sliced
  • 5 tablespoons Kewpie mayonnaise (see Tip), plus more to taste
  • 1 teaspoon grated lemon zest
  • 1 teaspoon fresh lemon juice, plus more to taste
  • Freshly ground black pepper
  • Preparation
  • Step 1: In a medium saucepan, cover the potatoes with cold water by at least 1 inch. Add a few big pinches of salt. Bring to a boil over high heat. Gently lower the eggs into the pot. Cover, reduce to a bare simmer, and cook until the potatoes are tender and show no resistance when pierced with a knife or cake tester, 10 to 12 minutes. Drain the potatoes in a colander and spread in a single layer on a large rimmed baking sheet. Immediately sprinkle with vinegar and sugar. Set aside until completely cool, at least 15 minutes. Transfer the eggs to a bowl of ice water and peel when completely cool.
  • Step 2: Meanwhile, toss the cucumber with a big pinch of salt in the bottom of a large bowl and set aside until the potatoes are cool.
  • Step 3: When the potatoes are cool, add them to the bowl with the cucumber and lightly mash with the back of a fork until some bite-size chunks still remain.
  • Step 4: Add carrot, corn, radish, scallion, mayonnaise, lemon zest and juice. Squeeze the hard-boiled eggs through your clean fingers to break them up, or chop them with a knife and add them to the salad. Stir together and season with pepper, more salt, sugar, vinegar, lemon juice or mayonnaise, or a combination, to taste.
  • TIP
  • Kewpie is a Japanese brand of mayonnaise with a thicker texture, and tangier, though any mayonnaise you prefer will work in this recipe.