- Put mung bean noodles in a bowl and pour in lukewarm water to cover. Let soak until soft and pliable (about 15 minutes). Drain.
- Add noodles to a large pot of boiling water. Reduce to medium heat; cook until noodles are plump and glasslike (3 to 5 minutes). Drain in a colander; rinse with cold water; drain again.
- Cut into 3- or 4-inch lengths. Chill.
- Pour oil into a hot wok or skillet. Add chicken; saute until it loses its pink color. Break into small morsels. Season with salt and pepper. Let cool.
- Mix together chile, lime juice, nam pla, sugar, shallots and cilantro; pour over noodles and mix thoroughly. Add the chicken, shrimp and chilled noodles; mix well.
- Serve on a bed of thinly shredded lettuce.
- Garnish with the optional crisp-fried shallots.