In small bowl, mix together soy sauce, orange juice, dry sherry, cornstarch, and sugar. Set aside.
In a large nonstick skillet, heat oil over medium-high heat. Add tofu; stir-fry 2 minutes, or until lightly browned. Add carrots, snow peas, mushrooms, garlic, and gingerroot; stir-fry 3 to 5 minutes, or until vegetables are crisp-tender. Stir in soy mixture, and heat to boiling; cook 1 minute. Garnish with sliced green onion.