The secret ingredient in stir fry beef is a Chinese cooking and culinary technique that is called velveting.
Velveting is the secret in good stir fry beef and uses cornstarch and baking soda or egg whites in a marinade to break down tough fibers in the beef and to also lock in moisture and create a silky and tender texture.
The velveting process of the meat, when making stir fry beef transforms the beef and even economical or cheap cuts of beef and prevents the beef from drying out over high heat.
To velvet the beef for stir fry beef.
Cut the beef against the grain into thin and even strips so that the beef cooks quickly.
Then for 1 pound of beef, mix in 1/2 teaspoon of baking soda and allow it to sit for 10 minutes to 15 minutes, which tenderizes the meat.
Then rinse the meat well and pat completely dry.
Toss the dried beef with a splash of some soy sauce, Shaoxing wine or other aromatics.
And for the protective coating, add 1 egg white and 1 to 2 teaspoons of cornstarch.
Massage the protective coating into the beef, which creates a protective barrier and seals in juices when the beef hits the hot wok.
The instructions for making stir fry beef includes.
Toss your thinly sliced beef with the soy sauce, cornstarch, and baking soda. Let it marinate on the counter for 10–15 minutes.
Whisk all the sauce ingredients in a small bowl until smooth and set aside.
Heat 1 tablespoon of oil in a large skillet or wok over medium-high heat. Add the marinated beef in a single layer.
Let it sear undisturbed for 1–2 minutes, then stir for another minute until just browned.
Remove the beef to a clean plate.
Add the remaining 1 tablespoon of oil to the same pan.
Add your vegetables and the white parts of the green onions, stirring frequently for 3–4 minutes until they are slightly softened but still crisp.
Return the beef to the pan.
Give your sauce a quick stir (to re-mix the cornstarch) and pour it over the meat and vegetables.
Toss everything constantly for 1–2 minutes, or until the sauce bubbles and thickens into a glossy glaze.
Remove from heat, garnish with the remaining green onion tops and sesame seeds, and serve.