Slice the flank or skirt steak against the grain into thin strips and marinate with soy sauce, peanut oil, and cornstarch for 10 minutes.

In a bowl, whisk together chicken stock, Shaoxing wine, dark soy sauce, brown sugar, and cornstarch until smooth.

Bring 1 inch of water to a boil in a nonstick skillet and steam the broccoli florets for about 1 minute until bright green.

Heat peanut oil in the skillet and sear the marinated beef for about 30 seconds each side until browned.

Add garlic and ginger to the skillet and stir until fragrant, then add broccoli and pour the sauce over.

Stir continuously until the sauce thickens, then serve immediately over rice or noodles.