Slice the beef. Freeze the beef for 20–30 minutes to firm it up. Slice thin, against the grain, into 1/4-inch strips. This keeps it tender.

Mix the sauce. In a bowl, whisk soy sauce, broth, oyster sauce, rice vinegar, honey, sesame oil, black pepper, and 1 tablespoon cornstarch until smooth. Taste and adjust sweetness or salt.

Marinate the beef. Toss the sliced beef with 1 tablespoon cornstarch and 3 tablespoons of the sauce. Let sit 10–15 minutes while you prep the broccoli. This quick velvet helps lock in moisture.

Blanch or steam the broccoli (optional but recommended). Bring a pot of salted water to a boil. Cook broccoli for 1–2 minutes until bright green and crisp-tender. Drain and set aside. Alternatively, steam for 2–3 minutes. This step speeds up the stir-fry and keeps broccoli vibrant.

Heat the pan. Set a large skillet or wok over medium-high heat. Add 1 tablespoon oil and swirl to coat.

Sear the beef in batches. Add half the beef in a single layer. Cook 1–2 minutes per side until browned but still slightly pink. Remove to a plate. Repeat with remaining oil and beef. Don’t overcrowd or the beef will steam.

Aromatics time. Reduce heat to medium. Add garlic, ginger, and red pepper flakes (if using). Stir 20–30 seconds until fragrant. Don’t let them burn.

Build the stir-fry. Return broccoli and beef to the pan along with any juices. Pour in the remaining sauce and bring to a simmer. Stir 1–2 minutes until the sauce thickens and coats everything. If it thickens too much, splash in a little broth or water.

Finish and serve. Turn off heat. Toss in green onions. Taste and adjust with a squeeze of lime, more soy, or a pinch of sugar. Serve hot over rice, topped with sesame seeds.