Place 1 halveed seeded spaghetti squash in a microwave-safe bowl with 2 tablespoons water; cover and microwave until tender, 15 minutes. Let cool, then scrape with a fork. Puree 1/2 cup chopped carrots with 1/4 cup water, a 1-inch piece of ginger, the whites from 3 scallions, 2 tablespoons sesame oil, sysauce and rice vinegar and 1 tablespoon brown sugar. Toss with the squash and scallion greens. Top with toasted sesame seeds.