Heat a large skillet or wok coated with cooking spray over medium-high heat. Add ginger and garlic cloves; stir-fry 30 seconds. Add mushrooms and tofu; stir-fry 2 minutes. Add carrot, corn, and water chestnuts; stir-fry 1 minute. Stir in soy sauce and vinegar; cook 2 minutes. Stir in green onions, sesame oil, pepper, and salt.