Noodles: Most types are interchangeable, but two - rice vermicelli
and bean thread noodles - can be crisp-fried. Egg noodles are rarely
seen in Vietnam, where only rice flour noodles are used. Dried noodles
are usually soaked in cold water for 10-20 minutes until softened before
cooking; in general, the weight doubles after soaking. After draining,
cooking is usually brief.