In a shallow dish, whisk together all the marinade ingredients. Set aside.
Peel carrots and trim off the tops. Cut the carrots into pieces 3 inches long and 1/4 inch thick. Put the carrots in a saucepan, add water to cover, and bring to a boil. Boil until al dente, about 5 minutes. Drain and immediately add them to the marinade. Mix well and set aside to marinate for 3 hours.
In a skillet, bring 2 cups water to a boil, add the scallion tops, and boil for 1 to 2 minutes, or until wilted. Drain and refresh under cold running water. Dry on paper towels.
Divide the carrots into 8 bundles. Tie each bundle with a scallion top and place them on a decorative platter. Pour the remaining marinade over the carrots. Serve at room temperature.