Mongolian Beef Stir-Fry is a quick and easy version of the classic recipe. Instead of marinating the beef, it is simply stir-fried with the sauce and green onions. This saves time without compromising on flavor. The beef is cooked until it is tender and coated in the delicious sauce. Serve it with steamed rice or noodles for a satisfying and flavorful meal that can be prepared in no time.