1. In a large bowl, whisk together 2 tablespoons of cornstarch with 3 tablespoons of water.
2. Once well combined, toss the beef pieces into the bowl and mix together.
3. In a small bowl, whisk together the remaining 1 tablespoon cornstarch with the soy sauce, brown sugar, garlic, and ginger—then set the sauce aside.
4. Heat a large nonstick sauté pan over medium heat.
5. Once hot, add 2 teaspoons of the olive oil and the beef, letting it cook for 8 to 12 minutes, stirring often.
6. Once the beef is cooked, remove it from the pan and set it aside, then return the pan to the hot stove.
7. Once the pan is hot again, add the remaining 2 teaspoons of olive oil, broccoli, and onion, letting them cook for 5 to 10 minutes.
8. Once the onions are fragrant and the broccoli is tender, add the beef back into the veggie pan, along with the sauce.
9. Once everything is in the pan, turn up the heat slightly, bringing the sauce to a boil, and let it thicken for 1 to 2 minutes.
10. Once the sauce is thick, serve your stir-fry and enjoy!
