Step 1

Sprinkle the cornstarch, salt, and pepper over the beef and toss to combine. Marinate at room temperature for 20 minutes.

Step 2

In a small bowl, prepare the sauce by mixing together the soy sauce, water, brown sugar, and rice vinegar.

Step 3

In a wok over medium-high heat, heat the peanut oil.

Step 4

Add the beef and fry just until the surfaces turn brown.

Step 5

Add the ginger and garlic, and stir-fry until fragrant, 2 or 3 seconds.

Step 6

Add the sauce and stir to coat the beef.

Step 7

Turn off the heat and add the scallions. Give it one last stir to very lightly heat up the scallions but not to cook them.

Step 8

Transfer the dish to a serving plate.