Whisk together soy sauce, mirin, honey, rice vinegar, minced garlic, and fresh ginger in a small bowl. Set your teriyaki beef sauce aside—this is your foundation. The aromatics should perfume your kitchen already, signaling what's coming.

Pat your beef slices completely dry with paper towels; moisture is the enemy of a proper sear. Heat vegetable oil in a large skillet over high heat until it shimmers visibly. This step takes roughly 2 minutes and separates mediocre results from exceptional searing.

Working in two batches to avoid crowding the pan, sear the beef for 90 seconds per side maximum. Each piece should develop a caramelized crust while the interior stays pink and tender. Transfer seared beef to a clean plate and resist the urge to fidget with it.

In the same skillet, add broccoli florets and red bell pepper slices, stirring constantly for 3-4 minutes until they're bright and crisp-tender. The fond left from the beef creates instant umami for your vegetables. This stunning beef comeback begins here as aromatics bloom.

Return the beef to the skillet and pour in your prepared sauce, then add cornstarch mixed with water to create the slurry. Toss everything continuously for 2-3 minutes until the sauce thickens and coats each ingredient with glossy perfection. The transformation is CIA-level precise in its timing.

Drizzle sesame oil over everything and scatter chopped green onions across the top. Taste and adjust seasoning with additional soy sauce if needed—your palate is the final authority here.

Serve immediately over steamed rice, garnishing generously with sesame seeds. The moment between plating and eating should be measured in seconds, not minutes.