A substitute for oyster sauce in beef and broccoli is hoisin sauce or a mix of soy sauce with sugar or honey or even some vegetarian mushroom sauce.
Other good substitutes for oyster sauce in beef and broccoli are sauces like coconut aminos, tamari or, which are good substitutes for umami, as well as add ginger, garlic and a touch of sweetness using some honey and or sugar for balance of flavor.
You can also use fish sauce or Worcestershire sauce for beef and broccoli to add depth and beef broth can be used for beef and broccoli to add a savory liquid base.
The brown sauce on beef and broccoli is a rich, umami packed mixture that is made of oyster sauce, soy sauce, light and dark soy sauce, beef/chicken broth, sugar and thickened with cornstarch and then flavored with aromatic ingredients like ginger and garlic, along with a hint of sesame oil and Shaoxing wine, which creates the nice signature Chinese takeout taste.
The key ingredients in the brown sauce on the beef and broccoli are oyster sauce, which provides deep savory flavor or umami and body, soy sauce light and dark, which adds color, depth and saltiness, beef/chicken broth, which is the liquid base for the sauce, sugar to balance the saltiness with a touch of sweetness, cornstarch to create the signature glossy, thick texture that is a slurry with water, aromatics like garlic and ginger, which are essential for fragrant flavor and sesame oil/Shaoxing wine to add nutty aroma and complexity.
To make the brown sauce for beef and broccoli, whisk together some soy sauce, oyster sauce, broth, sugar and wine if using wine.
Next stir in a cornstarch slurry of cornstarch mixed with cold water and saute aromatics by briefly cooking garlic and ginger and add liquid mixture and cook and simmer until thickened.
Once finished, toss the brown sauce with beef and broccoli.
The sauce that is on Panda Express beef and broccoli is savory, classic ginger soy sauce.
The savory and classic ginger and soy sauce that Panda Express uses on their Beef and Broccoli is a rich that contains soy source, fresh ginger, garlic as well as often oyster sauce, a thickener like cornstarch and brown sugar, which creates a signature rich, slightly sweet and umami flavor.
The actual recipe for Panda Express ginger soy sauce is not fully known s proprietary, although the core of the Panda Express Ginger soy sauce is a savory, slightly sweet brown sauce that is built on a foundation of soy, ginger and garlic, which creates the familiar Panda Express restaurant taste.
You can make a similar sauce to use on beef and broccoli by using the following ingredients which include.
A base of soy sauce, ginger and garlic.
Brown sugar or sugar for sweetness.
Oyster sauce for Umami and Depth.
Cornstarch or modified food starch for thickener.
Chicken broth or water for the liquid.
And aromatic ingredients like sesame oil and rice vinegar.
To make a similar copycat sauce to the sauce that Panda Express uses on beef and broccoli you start by marinating the beef with soy sauce, Shaoxing wine and sometimes cornstarch to tenderize the beef.
Then you whisk together ingredients like oyster sauce, soy sauce, sugar, broth, rice vinegar and corn starch.
And then the beef is stir fried quickly, then you add the broccoli.
The sauce mixture is then poured in and cooked until it thickens up into a glossy glaze, coating the beef and broccoli.