origin: Traditional (National&Religious)
To toast sesame seeds, heat a small, dry skillet over medium-high heat. Stir in the sesame seeds. Shake the pan occasionally to prevent burning the seeds. The seeds are toasted when they turn a shade darker and smell nutty. It should take about 4 minutes, give or take.
Bring a large pot of water to a boil and set up a large bowl of ice water. Drop the beans into the boiling water. Cook, stirring occasionally, for 4 to 6 minutes. Remove beans with tongs or a slotted spoon and plunge into the ice water. Remove the beans from the ice water after a few minutes, when the beans are cool. Pat dry. Slice the beans, at an angle, into bite-size pieces.
Make the glaze. Heat a small skillet over medium-high heat for several minutes. Pour in soy sauce (it will sizzle furiously). Stir in sugar and vinegar. Stir in slurry. The mixture should quickly thicken, probably in less than a minute. Remove from heat and set aside. Heat the sesame oil in a large skillet over medium-high heat. Add the green beans and stir to coat with the oil. Saute for another minute or two. Stir in the glaze, tossing to coat and cook just until heated through. Remove from heat. Place the beans on a serving platter and sprinkle with the toasted sesame seeds.