• Slice scallions, for optional garnish
Set the pork on a large plate and freeze until the meat is firm and partially frozen, 20 to 30 minutes. Meanwhile, in a medium bowl, whisk together 2 tablespoons soy sauce, the cornstarch and 1/2 teaspoon pepper.
Using a chef’s knife, cut the partially frozen pork crosswise into slices about 1/8 inch thick. Add the pork to the soy-cornstarch mixture and stir to coat; let stand at room temperature for 15 minutes. Meanwhile, in a small bowl, whisk together the hoisin, remaining 1 1/2 tablespoons soy sauce, 1/2 teaspoon pepper and 1/3 cup water; set aside.
In a 12-inch skillet over medium-high, heat 2 tablespoons oil until barely smoking. Add the broccoli and cook, stirring occasionally, until charred in spots and tender-crisp, 4 to 6 minutes. Transfer to a large plate; set aside.
In the same skillet over high, heat the remaining 2 tablespoons oil until barely smoking. Add the pork in an even layer and cook without stirring until golden brown on the bottom and the pieces release easily from the skillet, about 2 minutes. Add the ginger and garlic, and, using a metal spoon or spatula, stir and scrape up the pork and cook until the ginger is aromatic, about 30 seconds. Add the broccoli and hoisin mixture. Cook, stirring, until the sauce is syrupy and the pork is tender, about 3 minutes. Off heat, taste and season with salt and pepper. If desired, garnish with toasted sesame seeds, sesame oil or scallions — or a combination of the three — before serving.
