Creating Mongolian Beef Magic is easy if you follow these straightforward steps:

1. Prep the Beef: Slice the flank steak thinly against the grain and season it with salt and pepper.
2. Coat with Cornstarch: Place the sliced beef in a bowl and toss with cornstarch, ensuring each piece is coated evenly.
3. Heat the Oil: In a large skillet or wok, heat the vegetable oil over medium-high heat.
4. Cook the Beef: Add the coated beef to the hot skillet in a single layer. Cook for about 2-3 minutes undisturbed until browned, then flip and cook for another 2-3 minutes until cooked through. Remove the beef from the skillet and set aside.
5. Sauté Garlic and Onion: In the same skillet, add the minced garlic and sliced green onions. Sauté for about 1 minute until fragrant.
6. Make the Sauce: In a small bowl, whisk together the soy sauce, brown sugar, rice vinegar, sesame oil, and ginger.
7. Combine: Pour the sauce into the skillet with the garlic and onions. Allow it to simmer for about 2-3 minutes until it thickens slightly.
8. Add Back the Beef: Return the cooked beef to the skillet, stirring well to coat in the sauce. Let it cook for another minute to soak up the flavors.
9. Serve Immediately: Spoon the Mongolian beef over a bed of rice or noodles. Garnish with extra green onions if desired.

Following this recipe will guide you toward creating a delicious meal that showcases the wonders of Mongolian Beef Magic.