There are two basic types of food in Japan, washoku (traditional Japanese cooking) and yoshoku (Japanese adaptations of western food). When I lived in Japan one of my favorite examples of yoshoku was Japanese potato salad. It differs from American potato salad in a number of ways, most especially the type of potato used. In America we like to use waxy potatoes so that the potatoes have solid chunks in the salad. In Japan, they use starchy potatoes, and the salad has a texture more like mashed potatoes with little crunchy bits from the vegetables which are added into the salad.
I consulted two recipes for this dish, Jane Lawson’s Yoshoku: Japanese Food Western Style and the Serious Eats website (http://www.seriouseats.com/recipes/2015/06/japanese-potato-salad-recipe.html ). I largely followed Serious Eats except that I thought the salad needed twice as much dressing as they suggested, and I also added more vinegar to taste at the end to make it more tangy.
3 Russet potatoes, peeled and cut into 1 inch chunks
2 Persian cucumbers, thinly sliced
1 carrot, quartered lengthwise and thinly sliced
¼ red onion, chopped
2 scallions, chopped
½ cup parsley, chopped
2 hard boiled eggs, chopped
¾ cup mayonnaise (preferably Kewpie, if you can get it, otherwise American mayonnaise is fine)
4 tsp. rice vinegar, plus additional to taste
1 tsp. hot mustard (I used Coleman’s English mustard)
Boil the potatoes in salted water until tender, around 10 minutes. Drain and cool.
Make the boiled eggs. I followed Michael Ruhlman’s advice in Egg, and it worked like a charm. (Put eggs in a saucepan, cover with at least an inch of water and bring to a boil. Then turn off the heat, cover, and let the eggs cook in the boiled water for 15 minutes. Drain, and put into an ice batch for 10-15 minutes, until fully cooled.)
Salt the cucumber slices in a colander and sprinkle with ½ tsp. of salt. Allow to drain for 10 minutes. Then press out the water with paper towels.
Prepare the dressing by mixing together the mayonnaise, rice vinegar, and mustard.
Hand mash the cooled potatoes roughly, so a bit of texture remains. Mix in the chopped vegetables and egg, and then mix in the dressing. Stir to combine evenly. Add additional vinegar and salt to taste.