Soak bamboo skewers in water for 30 minutes.
In a small bowl, whisk together the soy sauce, garlic, oil, gingerroot, sugar, vinegar, sesame seeds, and pepper. Thread the steak cubes loosely onto 8 of the skewers and thread the remaining skewers crosswise through the middle of each scallion so that the scallions stand parallel to one another. Put the beef and scallion kebabs in a shallow dish just large enough to hold them, pour the marinade over them, coating them well, and let the kebabs marinate, chilled, turning them frequently, for 25 minutes.
Grill the kebabs on an oiled rack set about 6 inches over glowing coals, turning them, for 10 minutes. Alternatively, the kebabs may be broiled under a preheated broiler about 4 inches from the heat in the same manner.) Remove the beef and scallions from skewers before serving.
Recipe courtesy of Gourmet Magazine