One summer during college I was fortunate to spend three months in Japan traveling and eating my way around the country. Naming a favorite meal during my stay there would be impossible—there were just too many unforgettable dishes and restaurants. But if there was one overall type of Japanese food that I enjoyed the most, it would have to be yōshoku cuisine, which is Western food done Japanese-style.
One of the most popular yōshoku dishes, and one that can be easily made at home, is Japanese potato salad. When you compare the ingredient list of the Japanese version and the Western version, the ingredients are pretty similar. That's how most yōshoku dishes are—ingredient-wise, they look pretty much the same as the originals that inspired them. But they're almost always different in one way or another. In the case of the potato salad, the biggest difference is the texture, because in the Japanese version, they're always mashed. It also tends to include a wider variety of vegetables than you'd see in a typical American potato salad, including cucumber, carrots, and corn; sometimes there's even ham mixed in.
Mayonnaise is a key ingredient in both versions, but for the yōshoku one, Japanese-style mayonnaise, such as Kewpie, is the mayo of choice for its extra creaminess and sweetness. You can find it at most Asian supermarkets, and I've noticed more and more Western supermarkets carrying it as well, but for some reason you can't track it down, it's easy enough to make at home. For the salad, it's mixed with rice vinegar and Japanese hot mustard. The rice vinegar adds even more tang to the dressing while helping to thin out the mayonnaise so it can be more easily mixed with the potatoes.
While Japanese-style mayonnaise plays an important role in this dish, you can't have potato salad without potatoes. The first step is to boil them, and there is a right and wrong way to do it. First, always start the potatoes in cold water. This allows them to heat up as the water does, resulting in more even cooking throughout. Second, it's important to season the cooking water so that the potatoes can absorb it well.
Next come the other salad ingredients. For this version, I'm keeping it simple with cucumbers, carrots, onions, eggs, and scallions, though there are plenty of Japanese potato salads that go well beyond this.
To prevent a watery salad, I thinly slice the cucumbers and season them with salt to draw out excess water before combining them with the other ingredients.
The last step is to gently mash the potatoes, leaving small chunks behind for texture, and then mix it all together.
It may look like your run-of-the-mill American potato salad, but the flavor is 100% Japanese.