Combine the beef with marinade ingredients and marinade for an hour. The beef should still be moist after it's done. If it looks
too dry, add a tablespoon of water.
Mix the sauce ingredients. Dissolve the sugar in hot water or stock, then stir in the soy sauces.
Heat ⅔ cups of oil in a wok over high heat. Just before the oil starts to smoke, spread the meat pieces evenly in the wok and
sear for 1 minute on each side, until crispy. Turn off the heat and transfer meat to a plate.
Drain the oil from the wok, leaving 1 tablespoon behind. Turn the heat to medium-high. Add the ginger and dried chilli peppers.
After about 15 seconds, add the garlic and white parts of scallions. Stir for another 15 seconds and add the premixed sauce.
Let the sauce simmer for about 2 minutes, and slowly stir in
cornstarch slurry mixture. Cook until the sauce has thickened
enough to coat the back of a spoon.
Add the beef and green parts of the scallions, and toss everything together for another 30 seconds. The scallions should just be
wilted, and there should be almost no liquid, as the sauce should all be clinging to the beef. If you still have the sauce,
increase the heat slightly and stir until thickened