Cut tofu into 1/2 inch cubes. Soak tree ears in warm water till soft. Drain & chop coarsely. Heat oil in a wok & when very hot add ginger, garlic & scallions. Add tofu, stirring quickly. Add tree ears, chilies & peas. Stir. Add sugar & vinegar & toss. Spoon mixture into a serving dish & sprinkle with sesame oil. Serve over rice.