Place the sliced beef into the medium bowl and add 1 tablespoon of oyster sauce, 2 teaspoons of soy sauce, ½ teaspoon sugar and stir. Sprinkle 1 teaspoon of cornstarch over the beef , add the minced garlic, and stir, set aside for 15 minutes to marinate.
Prepare the sauce by adding the remaining ingredients, 1 tablespoon of oyster sauce, 2 teaspoons soy sauce, ½ teaspoon sugar, 2 teaspoons cornstarch, and 2 tablespoons water and stir, set aside. Measure out 2 tablespoons of water, set aside.
Select a large frying pan (preferably with a lid*) and preheat the frying pan on medium heat for 3-5 minutes, the frying pan is ready when a drop of water sizzles in the pan.
Add 1 teaspoon olive oil, swirl the pan to coat, add the beef and garlic and spread the beef out and don’t touch it for 1 minute to give it a chance to sear.
After a minute, stir fry the beef so that both sides are browned (1 minute) and when approximately 75% cooked through, remove the beef from the frying pan and place in a clean bowl.
Add the broccoli to the frying pan (no need to clean), add 1-2 tablespoons of water (depends on how much liquid you have in the pan or clinging to the broccoli), and cover with a lid for 2 minutes for crisp broccoli or continue cooking for 1 more minute for softer broccoli.
Remove the lid, stir the broccoli, stir the sauce and add the sauce to the pan, return the beef to the frying pan and stir fry until the sauce thickens, it will take one minute and the sauce will be bubbly. During this time, push any pinkish pieces of beef to the bottom of the pan. Remove from heat and serve. If your sauce is too thick or thickens too fast, you can add a tablespoon of water to the sauce and stir.