Preheated grill to medium high. Pierce the steak all over with a fork. Combine 3 tablespoons each Ponzu sauce and wasabi mayonnaise with the vegetable oil in a large bowl. Add the steak; turn to coat. Let sit for 10 minutes. Meanwhile, Cook the rice as the label directs, adding the ginger to the cooking water.

Brush the grill grates with vegetable oil. Remove the stick from the marinade; and the scallions to the marinade and set aside. Grill steak, 8 to 10 minutes per side for medium rare. Transferred to a cutting board and let rest five minutes. Meanwhile, remove the scallions from the marinade and Grill, turning, until charred, about three minutes; transfer to the cutting board.

Fluff the rice with a fork; discard the ginger, if desired, and sister in the sesame seeds. Toss the cucumbers and carrots with the remaining 1 tablespoon Ponsou sauce and the vinegar. Thinly sliced the steak against the grain and roughly chopped scallions. Top each serving of rice with the cucumber-carrot mixture, steak, scallions and the remaining 1 tablespoon wasabi mayonnaise.