Make the Sauce: In a small saucepan, combine the broth, rice wine or sherry, sugar, cornstarch, and salt. Bring to boil, while whisking, until thick. Pour the sauce into a small plastic souffle cup, let cool, and pop the lid on. Refrigerate until ready to go.
Prepare the Veggies: In a flat, rectangular plastic microwave-safe plastic container, arrange the mushrooms, carrot, daikon, cabbage, and broccoli in neat, separate rows. Sprinkle the scallion, garlic, and ginger over the top. Seal the lid over the top and refrigerate until ready to go.
At work, school or home, microwave the veggies for 3 minutes on high. Remove and let steam in the container, while you microwave the sauce for 1 minute on high.
Pour the sauce over the veggies, stir with chopsticks, and enjoy.