In a large covered saucepan, bring 2 to 2-1/2 quarts of unsalted water to aboil over high heat.
2
Clean spinach and plunge into boiling water. After 1 minute, drain spinach in colander, flush with cold running water until chilled, then press lightly with palms of hands to remove excess water. Fluff spinach gently to loosen mass.
3
In medium-size bowl, cover rice noodles with 3 to 4 cups of heated water When pliable, after about 10 seconds use scissors to cut through loop ends or center of noddles, thereby cutting noodles into manageable 4- to 5-inch lengths. Swish bean threads to disperse in water. After another 10 to 15 seconds, when noodles are firm - like rubber bands to the touch - rinse briefly with cool water and drain again.
4
Heat skillet hot enough to evaporate a bead of water on contact. Add oil, swirl to coat pan, then reduce heat to medium-high. When hot enough to sizzle a bit of spinach on contact, add spinach and soy sauce and toss briskly another minute.
5
Add noodles and, using spatula, blend with several quick stirs until heated through. Add sesame oil, toss briskly to combine, then remove from heat.
