Cook the noodles in briskly boiling water for about five minutes. Drain. Plunge in iced water to stop the cooking so that the noodles don’t turn soggy. Drain.
Using kitchen shears, cut the noodles into about two-inch lengths. Keep the noodles in a strainer while you prepare the rest of the ingredients to allow excess water to fall off.
Mix all the ingredients for the dressing.
Toast the nuts in an oil-free pan. Transfer to a plate and cool.
Roughly chop the onion.
Thinly slice the tomato.
Finely slice the scallions.
Toss the noodles, onion, tomato, scallions and half of the nuts in a bowl.
Drizzle in the dressing. Toss lightly.
Sprinkle the rest of the nuts. Garnish with cilantro. Serve the glass (cellophane) noodle salad at once.