Created by Sue Lau on April 19, 2013
Step 1: While beef is still partially frozen, trim away excess fat and slice thinly.
Step 2: 2
Step 3: Whisk together marinade and pour over beef in a ziplock bag; refrigerate several hours or overnight.
Step 4: Whisk together sauce in a small bowl and keep nearby.
Step 5: Heat oil in a wok over high heat, stir-fry beef with marinade, mushrooms and onions until cooked through.
Step 6: Add sauce to wok, and cook, stirring, until sauce thickens.
Step 7: Serve stir-fry with steamed rice if desired.