Creating Sheet Pan Beef and Broccoli is straightforward and requires just a few simple steps:

1. Prep the Oven: Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper for easier cleanup.
2. Prepare the Beef Marinade: In a bowl, combine 2 tablespoons of soy sauce, brown sugar, cornstarch, minced garlic, minced ginger, and black pepper. Mix well until smooth.
3. Marinate the Beef: Add the sliced flank steak to the marinade, ensuring that all pieces are coated well. Let it marinate for at least 10 minutes while you prepare the vegetables.
4. Prepare the Broccoli: In a separate bowl, toss the broccoli florets with 1 tablespoon of olive oil and a pinch of salt and pepper. This will enhance their flavor during roasting.
5. Assemble on Baking Sheet: Spread the marinated beef and broccoli on the prepared baking sheet in a single layer. Ensure the pieces are evenly spaced so they cook properly.
6. Roast in the Oven: Place the baking sheet in the preheated oven and roast for 15-20 minutes, or until the beef is cooked through and the broccoli is tender-crisp.
7. Toss and Garnish: Once done, remove the sheet from the oven. Give everything a good toss and garnish with sesame seeds and sliced green onions, if desired.
8. Serve and Enjoy: Transfer the beef and broccoli to serving plates and enjoy this amazing dish immediately.

These steps will guide you to create this incredible sheet pan meal effortlessly, allowing you to savor the delightful flavors it offers.