Bring 2 quarts water with 2 tsp. kosher salt to a boil.
Slice the steak in half lengthwise and then cut crosswise into thin slices. In a medium bowl, stir 1 Tbs. of the soy sauce with the sherry, cornstarch, and 1/2 tsp. salt. Add the steak, toss to coat, and let sit for 10 minutes.
Meanwhile, blanch the broccoli in the boiling water until it softens to a tender crunch, 2 to 3 minutes. Drain in a colander and then rinse under cold water until the broccoli cools.
Set a large, heavy skillet or a large wok over high heat for 1 minute. Pour in 2 Tbs. of the oil and, when it starts to shimmer, add the beef. Cook the beef, stirring frequently, until it loses most but not all of its raw color, about 2 minutes. Transfer to a large plate. Add the remaining 2 Tbs. oil and the garlic, ginger, chile flakes, and 1/4 tsp. salt. Stir-fry for 30 seconds. Add the broccoli and 3 Tbs. water and cook, stirring to incorporate any browned bits on the bottom of the pan, until the broccoli warms through, about 1 minute. Stir in the beef, the oyster sauce, and the remaining 2 Tbs. soy sauce; cook, stirring, for 1 minute. Serve immediately.
nutrition information (per serving):
26, Fat Calories
230, Saturated Fat
23, Monounsaturated Fat
9, Polyunsaturated Fat
Photo: Scott Phillips