Bulgogi

Stir together soy sauce, sugar, sesame oil, white and pale green scallions, garlic, ginger, and 2 tablespoons sesame seeds in a bowl until sugar is dissolved. Add steak and toss to coat, then marinate 15 minutes.

Heat vegetable oil in a 12-inch heavy skillet over high heat until just smoking, then add steak in 1 layer and sauté, turning over occasionally, until browned and just cooked through, about 5 minutes total. Transfer to a platter and sprinkle with scallion greens and remaining 1 tablespoon sesame seeds, then serve with accompaniments.