Marinate the Beef: Slice flank steak against the grain into thin strips. Combine beef with soy sauce, peanut oil, and cornstarch in a bowl. Allow to marinate for 10 minutes.

Prepare the Sauce: Whisk together chicken stock, Shaoxing wine, dark soy sauce, brown sugar, and cornstarch in a separate bowl. Set aside.

Steam the Broccoli: Bring water to a simmer in a skillet. Add broccoli florets and cover, steaming for about 1 minute. Transfer to a plate.

Cook the Beef: In the same skillet, increase heat to medium-high, add marinated beef in a single layer, cooking for about 30 seconds. Flip and cook until lightly charred, about 1-2 minutes.

Add Aromatics: Stir in minced garlic and ginger, cooking for about 30 seconds until fragrant.

Combine and Thicken: Return steamed broccoli to skillet, pour in the sauce, and cook for an additional minute until the sauce thickens.

Serve: Transfer to a serving plate and enjoy hot over freshly steamed rice.