Edamame disappear quickly when simply salted, but they take on added appeal when tossed with chile flakes. Boil them and set them out while you put the finishing touches on the meal.
Pulse red-pepper flakes in a spice grinder until finely ground. Mix with salt and sugar in a small bowl.
Bring a large pot of water to a boil. Add frozen edamame, and cook until bright green and heated through, about 4 minutes. Strain, and transfer to a large bowl. Toss with chile-salt mixture, and serve.