In a medium container, whisk together the sugar, white vinegar and water until dissolved. Add the grated carrots and julienne red onion. Hold chilled at 40°F or below until service. Prepare these pickled vegetables at least 30 minutes before serving, and up to 1 day beforeserving. Drain off the liquid before assembling the sandwiches.
Preheat the oven to 350°F. Spray 2 full-size 2-inch steamtable pans with pan release spray. Place 5 pounds of turkey meatballs in each prepared pan.
In a 2-quart liquid measuring pitcher combine the Kikkoman Low Sodium Gluten-Free Sweet & Sour Sauce and the Kikkoman Rice Vinegar. Stir until well combined. Divide the sauce evenly between each pan of meatballs. Stir the meatballs until they are evenly coated with the sauce. Bake, uncovered, in the preheated oven for about 20-25 minutes, or until the sauce bubbles and begins to glaze the meatballs.
CCP: Cook to a minimum internal temperature of 135°F.
CCP: Hold hot, covered, at 135°F or higher.
To assemble the sandwiches place a flatbread on a serving tray and place 4 meatballs down the center of the flatbread. Lay 4 slices of cucumber on the flatbread along one side of the meatballs. Place 3⁄8 cup of the pickled carrot and red onion along the other side of the meatballs. Sprinkle 1 tablespoon of the rough chopped cilantro over the top of the meatballs.