Creating Chinese Beef and Broccoli can be straightforward if you follow these clear steps:

1. Prep the Beef: Slice the flank steak or sirloin thinly against the grain for tenderness. Set aside.
2. Marinate the Beef: In a bowl, combine soy sauce, oyster sauce, cornstarch, brown sugar, and black pepper. Add the beef slices and let them marinate for at least 10 minutes.
3. Heat the Oil: In a large skillet or wok, heat the vegetable oil over medium-high heat.
4. Cook the Beef: Add the marinated beef to the pan in a single layer. Sear for 1-2 minutes until browned and just cooked through. Remove from the skillet and set aside.
5. Sauté the Vegetables: In the same pan, add a bit more oil if necessary. Sauté the minced garlic and ginger for about 30 seconds until fragrant.
6. Add Broccoli: Throw in the broccoli florets and stir-fry for about 3-4 minutes until bright green and tender-crisp.
7. Combine: Return the beef to the pan along with the marinade and add beef broth or water. Stir everything together until the sauce thickens and the beef is heated through.
8. Serve Hot: Transfer the beef and broccoli to a serving dish, garnishing with sesame seeds if desired.

Following these simple steps will guide you in creating an incredible dish, perfect for any night of the week!