Preheat oven to 350°F. Place chicken thighs on parchment-lined sheet pans. Roast chicken thighs until partially cooked to an internal temperature of about 140°F. Remove from oven, drain grease, and toss in Kikkoman Sushi Sauce. Place in oven and finish roasting until the internal temperature reaches 165°F. Transfer cooked chicken thighs to full-size 2-inch steamtable pans. Hold at or above 140°F until service.
Just before service sprinkle with sliced scallions.