A salad like this would be made in Japan with Udon (buckwheat) noodles or in China with thick fresh egg noodles—certainly use these noodles if available, preparing them according to package directions. Spaghettini, sometimes called thin spaghetti on the package, makes a good substitute. But remember, before adding the cooked spaghettini to the dressing, rinse the noodles under cold running water and then drain well.
Salt, to taste
¼cupsmooth peanut butter
2tablespoons chopped, peeled, fresh ginger
1tablespoon dark Asian sesame oil
¼cup very hot water
3scallions, trimmed, green and white parts separated, and each very thinly sliced
3tablespoonssesame seeds, toasted (optional)
1tablespoon chopped fresh cilantro (optional)
Bring a large pot of water to a boil for the pasta. Add a little salt. When the water is boiling, add the spaghettini, stirring. When the pasta is tender, drain well in a colander. Rinse very thoroughly under cold running water. Drain the pasta well.
Meanwhile, combine the peanut butter, soy sauce, ginger, vinegar, sesame oil, and hot-pepper sauce in a food processor. Process until all the ingredients are blended, stopping the machine once or twice to scrape down the sides of the work bowl with a rubber spatula. Add the very hot water and process until the sauce is smooth, again stopping the machine once or twice to scrape down the sides of the work bowl. Scrape the sauce into a medium bowl.
Add the white part of the scallions and the cooled and drained spaghettini to the sauce. Toss gently with 2 forks to thoroughly coat the pasta. Let stand at room temperature for 30 minutes, tossing once or twice.
Before serving, taste the salad and adjust the seasoning if needed with a little more soy sauce, hot-pepper sauce, and/or sesame oil. Garnish with the scallion greens and with sesame seeds and cilantro if desired.