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

Prepare the sauce by mixing chicken or beef stock, Shaoxing wine, dark soy sauce, brown sugar, and cornstarch until smooth.

Steam the broccoli in a skillet with boiling water for about 1 minute until bright green and tender.

Increase heat and cook marinated beef in the skillet until browned, about 1-2 minutes.

Stir in minced garlic and ginger, and cook for another 30 seconds.

Mix in the steamed broccoli and sauce, stirring until well-coated and the sauce thickens.

Serve hot over rice or noodles.