Start by slicing the beef thinly against the grain. This will help it cook quickly and stay tender. If you're using flank steak, make sure to trim any excess fat before slicing. Once sliced, set the beef aside.

In a large pot, bring water to a boil and add a pinch of salt. Add the broccoli florets and cook for 2-3 minutes until they’re bright green and just tender. Drain and set aside.

Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Once the oil is hot, add the sliced beef in a single layer. Let it sear for 1-2 minutes without stirring to get a nice brown crust. Stir occasionally until the beef is browned and cooked through. Remove the beef from the pan and set it aside.

In the same skillet, add a bit of sesame oil and sauté the garlic and grated ginger for about 30 seconds or until fragrant. Then, pour in the soy sauce, oyster sauce, brown sugar, and water (or broth). Stir to combine. Bring the sauce to a simmer, then add the cornstarch mixed with a bit of water to thicken it.

Add the beef and broccoli back into the skillet, tossing everything together to coat the beef and broccoli in the sauce. Let it simmer for another 2-3 minutes, allowing the sauce to thicken and everything to heat through.

Once everything is well coated and the sauce has thickened, remove from heat. Serve your delicious beef and broccoli over steamed rice or noodles or on its own.