Add thinly sliced top sirloin, cornstarch, soy sauce, & rice wine to a medium bowl. Season with white pepper. Stir to combine, coating the beef thoroughly & evenly. Set aside to rest at room temperature while you prepare the rest of the ingredients. This is a great time to prepare all of the stir fry vegetables, chopping & slicing everything as indicated in the Ingredients List, above.

Add the beef stock cornstarch, dark brown sugar, oyster sauce, soy sauce, & 1 teaspoon of the sesame oil to a small bowl or jar. Whisk or shake to combine well. Set aside. Add the remaining 1 teaspoon sesame oil to a small saucepan over medium-high heat. Once hot, add the garlic & cook until fragrant & lightly browned, 30 seconds – 1 minute. Stir in the beef stock mixture & cook, stirring occasionally, until thickened, 4-5 minutes. Remove from the heat & set aside.

Meanwhile, as the stir fry sauce thickens, begin the stir fry. Add 1 teaspoon of the grapeseed oil to a wok or large skillet over medium-high heat. Once hot & shimmering, add the carrots & broccoli. Lightly season with a small pinch of salt & cook, stirring often, until vibrantly colored & softened slightly, 3-4 minutes. Transfer to a large plate or bowl & set aside. Add another 1 teaspoon of oil to the wok or skillet & return to medium-high heat. Once hot & shimmering, add the sliced red onion, bell pepper, mushrooms, cabbage, & snow peas. Lightly season with a small pinch of salt & cook, stirring often, until softened slightly, about 3 minutes. Transfer to the same large plate or bowl as the broccoli & carrots & set aside.

Add the remaining 2 teaspoon of oil to the wok or skillet & reduce the heat to medium. Once hot & shimmering, add the marinated beef from Step 1. Shake the pan to separate the slices of beef for even browning. Cook, tossing & stirring occasionally, just until browned. While stirring, pour the prepared stir fry sauce from Step 2 into the skillet. Add the stir fried vegetables back into the skillet. Cook 1-2 minutes longer, tossing & stirring frequently to bring the beef and vegetable stir fry together. Remove from the heat.

Immediately, spooning the beef and vegetable stir fry over rice or grain of choice. Finish with thinly sliced green onions & toasted sesame seeds as desired. Enjoy!