Mongolian Beef Stir-Fry is a classic Chinese dish that features tender strips of beef, stir-fried with green onions and a savory sauce. The beef is marinated in a mixture of soy sauce, ginger, garlic, and brown sugar, which gives it a rich and flavorful taste. This dish is quick and easy to make, making it perfect for a weeknight dinner. Serve it over steamed rice or noodles for a complete meal.