In a bowl, whisk together the soy sauce, rice wine, and cornstarch until dissolved. Then whisk in the brown sugar, ginger, and garlic. Add sliced beef to bowl and toss to coat. Set aside.

Warm oil in a heavy nonstick skillet or wok over medium-high heat. Add broccoli, season with a pinch of salt and stir. Pour the water in the pan and immediately cover. Let steam for 2-3 minutes. With a slotted spoon, transfer the broccoli to a separate plate. Set aside.

Allow pan to get very hot again. With tongs, add half the meat by spreading it out in the skillet (leaving most of the marinade still in the bowl), along with half the scallions.

Let the meat sear, without stirring for 1 minute. Turn meat over and cook for another 30 seconds. Transfer to a clean plate.

Repeat with other half of meat, allowing pan to get very hot again first (adding additional oil, if needed.)

After turning the meat, add the first plateful of meat, the rest of the marinade, the cooked broccoli, red pepper flakes, and remaining half of the scallions.

Stir over high heat for 1 minute to thicken, remove from heat. Check seasonings and add salt only if it needs it.

Serve immediately over cooked hot rice and enjoy!

NOTE: Mirin is a sweet Japanese rice wine, available at all Asian markets and most common grocery stores. If you can't find it, a good substitute would be dry sherry mixed with a bit of granulated sugar. (Avoid rice wine vinegar, which would give the sauce an acidic taste.)