Preheat the air fryer to 200°C (390°F).

Coat the thinly sliced flank steak with cornstarch.

Place the coated steak slices in the air fryer basket in a single layer.

Cook at 200°C (390°F) for 5 minutes on each side, or until crispy and cooked through.

Adjust cooking time as needed.

While the steak is cooking, prepare the sauce.

In a medium-sized saucepan, heat the vegetable oil over medium-high heat.

Add the ginger and minced garlic, and cook until fragrant.

Add the soy sauce, water, and brown sugar to the saucepan.

Whisk the ingredients together continuously until the sauce comes to a low boil and thickens slightly.

Once the steak and sauce are cooked, transfer the cooked steak to a bowl and pour the sauce over it.

Let it soak for 5 to 10 minutes.

To serve, use tongs to remove the steak from the sauce, allowing any excess sauce to drip off.

Serve the steak over cooked rice and green beans, and garnish with chopped green onions.

Optionally, drizzle extra sauce over the dish.