Trim excess fat from the steak and slice it thinly into bite-sized strips, cutting against the grain for tenderness.
1 pound flank steak
In a bowl or measuring cup, whisk together soy sauce, water, apple cider vinegar, sesame oil, brown sugar, cornstarch, ginger, garlic, and red pepper flakes until smooth. Set aside.
½ cup low-sodium soy sauce, ½ cup water, ½ teaspoon apple cider vinegar, ½ teaspoon toasted sesame oil, ¼ cup brown sugar, 3 tablespoons cornstarch, 4 garlic cloves, ¼ teaspoon crushed red pepper flakes, 1 teaspoon fresh ginger
Heat 1 tablespoon of olive oil in a large skillet or wok over high heat. Add the broccoli florets and stir-fry for 4–5 minutes until tender-crisp. Remove and set aside on a plate. Add the remaining 1 tablespoon of oil to the hot pan.
2 tablespoons olive oil, 4 cups broccoli florets
Place the steak in a single layer and let it sear undisturbed for 1 minute. Flip or stir, then cook for another minute until just browned. Work in batches if needed to avoid overcrowding the pan.
Once all beef is cooked, return it to the skillet. Add the broccoli back in and pour the sauce over everything. Stir well to coat evenly. Let it cook for 1–3 minutes, until the sauce thickens to a glossy finish.
Remove from heat and serve hot, sprinkled with sesame seeds. Pairs perfectly with steamed rice or noodles.
Sesame seeds