Slice the flank steak thinly against the grain and season with salt and pepper.

Bring a pot of water to a boil, add the broccoli florets, and cook for 2 minutes. Drain and transfer to an ice bath to retain color and crunch.

In a bowl, combine soy sauce, oyster sauce, beef broth, and cornstarch. Stir until cornstarch is dissolved.

In a skillet or wok, heat vegetable oil over medium-high heat. Add the sliced beef and cook for 3-4 minutes until browned. Remove from skillet and set aside.

In the same skillet, sauté minced garlic for about 30 seconds or until fragrant.

Return the beef to the skillet, add the broccoli, and pour in the sauce. Stir to combine and cook for an additional 2-3 minutes until the sauce thickens.

Remove from heat and serve warm over cooked rice.