Begin by slicing the beef against the grain into thin strips for maximum tenderness. Next, chop the white onion and red bell pepper into bite-sized pieces, and thinly slice the ginger and garlic. Gather all marinade ingredients and sauce components.

In a medium bowl, combine the sliced beef with soy sauce, sesame oil, Shaoxing wine, and cold water. Toss the beef until it’s well-coated with the marinade, and allow it to rest for 15 minutes.

After marinating, sprinkle cornstarch over the beef and toss it again until each piece is evenly coated. This will help create a crispy texture when you cook the beef.

In a bowl, whisk together the soy sauce, cornstarch, honey, hoisin sauce, oyster sauce, Chinese five spice, sesame oil, and cold water until smooth.

Heat a large skillet or wok over medium-high heat with a splash of oil. Carefully add the coated beef in batches, sauté for about 2-3 minutes until browned and crispy. Remove the beef from the skillet.

In the same skillet, toss in the sliced ginger and garlic, sautéing until fragrant. Then, add the chopped white onion and red bell pepper, cooking until soft.

Pour the prepared sauce into the pan with the cooked vegetables, stirring to combine well. Add the crispy beef back into the skillet and toss everything together for 1-2 minutes.

Remove the skillet from heat and transfer the Easy Mongolian Beef to a serving plate. Garnish with sliced green onions and sesame seeds if desired. Serve hot over rice or noodles.