This Beijing beef features bell peppers and onions tossed in a sweet, savory, spicy homemade stir-fry sauce that tastes just like Panda Express (or even better!).
Marinate the beef. Using a whisk, beat the soy sauce, egg whites, and 1 tablespoon cornstarch in a large bowl. Season to taste with salt and pepper. Add the sliced steak, cover with plastic wrap, and refrigerate for 30 minutes to marinate.
Make the sauce. Combine all the sauce ingredients in a bowl. Set aside.
Velvet the beef. Remove the beef from the marinade. Discard the marinade. Coat the beef slices with the ¼ cup of cornstarch. You can do this in two batches.
Cook the beef. Heat the cooking oil in a large skillet or wok to 350˚F. Once heated, add the beef and cook for 3-4 minutes or until done. Remove the beef slices with a slotted spoon and move them to a paper-lined plate to drain. Try not to crowd the pan and cook the beef in two batches.
Cook the veggies. Remove most of the oil from your skillet or wok, leaving about 2 tablespoons. Add the bell pepper and cook, stirring until crisp-tender, about 2 minutes. Stir in the garlic and cook for 15 seconds, or until fragrant. Remove the veggies from the skillet and transfer them to the plate with the beef.
Thicken the sauce. Add the sauce to the same skillet or wok. Cook for 3 to 5 minutes or until it thickens.
Put it all together. Stir the beef and veggies back into the pan with the sauce and toss to combine.
Serve. Serve warm, garnished with sesame seeds and spring onions.
Notes
Slice the steak against the grain for tender meat.
If needed, you can thicken the sauce with some cornstarch slurry.
If you do not have oyster sauce, you can use more hoisin or soy sauce.
Use low-sodium chicken stock because soy sauce is salty enough.