Slice flank or skirt steak thinly against the grain. In a medium bowl, combine beef with soy sauce, peanut oil, and cornstarch. Marinate for about 10 minutes.

In a separate bowl, whisk together chicken stock, Shaoxing wine, dark soy sauce, regular soy sauce, brown sugar, and a teaspoon of cornstarch until well combined.

Boil a small amount of water in a large skillet. Add broccoli florets, cover, and steam for about 1 minute until bright green and slightly tender. Set aside.

Increase heat to medium-high, add a splash of peanut oil, and add marinated beef in a single layer. Sear without stirring for 30 seconds, then flip and cook for another 30 seconds.

Add minced garlic and ginger and cook for about 30 seconds until fragrant.

Return steamed broccoli to skillet, add sauce mixture, and stir, cooking for about 1 minute until sauce thickens.