Japanese-Style Marinated Flank Steak

Lightly score one side of the steak on the diagonal and at 1-inch intervals. In a glass or ceramic baking dish large enough to hold the meat, combine the sake, mirin, soy sauce, ginger root, garlic and sugar. Marinate the steak at room temperature for 30 minutes, turning the meat once or twice.

Preheat the broiler for about 10 minutes before you plan to cook the steak. Remove the meat from the marinade, reserving the marinade. Broil the steak 3 inches from the heat for about 3 1/2 minutes on each side for medium rare steak. Let the steak rest for 5 to 10 minutes before thinly slicing it across the grain, on the diagonal.

Meanwhile, make the sauce: strain the marinade and measure out 1 cup; discard the remainder. Place the 1 cup marinade in a small saucepan and whisk in the cornstarch until smooth. Bring the mixture to a boil over moderate heat and cook, stirring constantly, for about 1 minute. Spoon 2 to 3 tablespoons of the sauce over the meat and serve the remainder separately.