Prepare the Ingredients:

1. Dice the onion and mince the garlic (and ginger, if using).
2. Cut the broccoli into bite-sized florets, and if desired, blanch them in boiling water for 2 minutes then drain—this step ensures they remain vibrant and crisp.

Brown the Beef:

1. In a large skillet or wok, heat the vegetable oil over medium-high heat.
2. Add the ground beef, breaking it up with a spatula. Cook until the beef is browned and no longer pink.
3. Season with a pinch of salt and pepper. Remove excess fat if necessary.

Sauté Aromatics and Broccoli:

1. Add the diced onion, minced garlic, and grated ginger to the beef. Sauté for 2–3 minutes until the onion softens.
2. Add the broccoli florets and stir-fry for another 3–4 minutes, until the broccoli is tender-crisp.

Create the Sauce and Combine:

1. Pour in the beef broth, soy sauce, oyster sauce (if using), and rice vinegar.
2. Sprinkle in the crushed red pepper flakes (if desired) and stir well to combine.
3. Allow the mixture to simmer for 3–4 minutes so the flavors meld and the sauce slightly thickens.

Finish and Serve:

1. Taste and adjust seasoning with additional salt and pepper if needed.
2. Garnish with toasted sesame seeds and sliced green onions.
3. Serve immediately over steamed rice or enjoy as is for a nutritious, satisfying meal.