In a plastic zipper bag, combine the steak with 1 tablespoon oil, 2 teaspoons soy sauce, and 2 tablespoons cornstarch.
1 pound flank steak, ¼ cup plus 1 tablespoon cooking oil, ¼ cup plus 2 teaspoons low-sodium soy sauce, 5 tablespoons cornstarch
Seal the bag and marinate in the refrigerator for 1 hour.
In a large skillet over medium-high heat, heat the remaining oil. Dredge the beef through the remaining cornstarch, shaking off any excess. Saute beef in batches until crispy, about 2 minutes per side, then transfer to a paper towel-lined plate.
1 pound flank steak
Add garlic and ginger and cook until fragrant, 1 minute. Stir in remaining soy sauce, water, brown sugar, and hoisin sauce. Bring the mixture to a simmer and allow it to thicken, 4 to 5 minutes.
¼ cup plus 2 teaspoons low-sodium soy sauce, 3 cloves garlic, 2 teaspoons fresh ginger, ⅓ cup water, 2 tablespoons brown sugar, 2 tablespoons hoisin sauce
Stir in broccoli, cover, and cook until tender, about 3 minutes.
1 head broccoli, 2 scallions
Add the scallions and return the beef to the skillet and stir until completely coated in sauce.
Serve over rice, garnished with sesame seeds.
Cooked jasmine rice, Sesame seeds