Cut pork along the grain into long 1-1/2- to 2-inch wide strips. Remove and discard any sinew but do not trim fat. Transfer pork to a large sealable plastic bag. Stir together remaining pork ingredients in a small bowl until combined well. Add to pork and turn to coat, then squeeze bag to eliminate as much air as possible and seal. Marinate pork, chilled, at least 4 hours but no longer than 24.
Put oven rack in lower third of oven and preheat oven to 375°F. Put 1/2 water in a 13 x 9 roasting pan and place a metal rack across top of pan (rack should not touch water).
Remove pork from marinade, reserving marinade, and arrange pork strips 1 inch apart on rack. Roast in oven 15 minutes.
Meanwhile, bring marinade to a boil in a 1quart saucepan, then boil 1 minute (marinade may look curdled). Remove from heat.
Brush both sides of pork with some marinade and roast 10 minutes more. Generously brush both sides of pork with marinade again and roast, basting 2 or 3 times, 10 minutes more
Increase oven temperature to 400°F and roast pork until strips are mahogany-colored and caramelized on edges, 10 to 15 minutes more (pork should roast for a total of about 50 minutes). Transfer to a cutting board and let stand, loosely covered with foil, 10 minutes.
Make dressing while pork roasts:
Blend together all dressing ingredients in a blender until smooth. Stir before using.
Cook noodles and beans for salad while pork finishes roasting:
Soak noodles in cold water to cover until pliable, about 15 minutes, then drain in a colander. Cut noodles in half with kitchen shears.
Cook beans in a 5 to 6 quart pot of boiling salted water, uncovered, until crisp-tender, ~4 to 5 minutes. Transfer with a skimmer or slotted spoon to a large bowl of ice and cold water to stop cooking, reserving cooking liquid in pot. Drain beans and pat dry.
Return bean-cooking liquid to a boil, then cook noodles, uncovered, stirring occasionally, until just tender, about 2 minutes. Drain noodles in colander and rinse under cold water to stop cooking. Drain noodles again, then spread out on paper towels and pat dry.
Cut as much pork as desired for salad across the grain into 1/4 thick slices. (Note: The intensity of the flavor fades when the pork is sliced, so cut it as needed. Unsliced pork keeps, wrapped in foil and chilled, up to 3 days, or frozen, tightly wrapped in plastic wrap and placed in a sealed plastic bag, up to 1 month)
Toss noodles with 1/4 cup dressing in a bowl. Toss long beans with 2 Tbsp dressing in another bowl.
Arrange pork, noodles, beans, and remaining salad ingredients on a large platter. Drizzle with some of dressing and serve remaining dressing on the side.