Yam Wun Sen (Cold Glass Noodle Salad)

Variations

• Yam wun sen boran: "ancient style", the plainer version with prawns and minced pork and no tomato or celery.
• Seafood: squid, mussels, crab meat. Only the blanching times change.
• Vegetarian: drop the meat and prawns for tofu, wood ear and shiitake. Replacing the fish sauce with soy and extra lime moves the flavour axis, so the quantities need re-balancing.
• Which glass noodle: mung bean is the standard. The sweet-potato starch noodles of Korean japchae are thicker and chewier and drink far more of the same dressing. They work, but make more dressing.
• Other Thai salads here: som tam is built by pounding in a mortar, and laap uses toasted ground rice to hold its juices. All three dress with no oil at all.

Tips

• The reason no cold noodle dish anywhere uses wheat is amylose. As daifuku sets out, starch is a mixture of straight-chain amylose and heavily branched amylopectin, and amylose is the molecule that recrystallises as things cool. Glutinous rice is effectively zero amylose, which is why mochi is still soft the next day; mung bean starch is over thirty per cent, close to double ordinary rice. So boiled and cooled it does not go soft — it sets firm, springy and non-sticky. The property that ruins a rice cake is the product here.
• You can see it by trying wheat. A gluten network gives up its water as it cools, so the noodles swell, clump, and carry the dressing only on the surface. It is the same reason naengmyeon is made with buckwheat, potato or sweet-potato starch.
• Ninety seconds, and no more. They have already been soaked, so boiling is only about getting heat to the core, and glass noodles go irreversibly soft past that point. The iced water is not optional either: the setting is part of the dish, so faster is better.
• How well you drain them decides the seasoning. A glass noodle has nothing on its surface to hold sauce, so a diluted dressing is simply a bland dish. A sieve is not enough; press them.
• Toss with your hands. Stirring with chopsticks or a spoon cuts the strands into short pieces. Lift from underneath and fold.
• Taste it cold. Naengmyeon says the same thing, and the reason is in serving temperature: "slightly too much?" is about right.
• Do not let it stand once dressed. Glass noodles go on taking up liquid — the point mie goreng makes from the hot end — so ten minutes is enough for the dressing to disappear and leave the noodles merely salty.