Bring a medium pot of well-salted water to a boil over high heat and cook the beans until crisp-tender, about 3 minutes; drain and cool under cold running water.
Heat the oil in a 12-inch skillet over medium-high heat. Add the scallions, garlic, and ginger; cook, stirring occasionally, until the garlic begins to brown, about 1 minute. Add the water chestnuts, red pepper flakes, and green beans and cook until warmed through, 2 to 3 minutes. Remove from the heat, add the soy sauce and sesame oil, toss, and serve.
nutrition information (per serving):
Photo: Scott Phillips