Step 1

Make the sauce and marinate the shrimp: Place the tamari or soy sauce, wine or sherry, desired amount of brown sugar, cornstarch, vegetable oil, and sesame oil in a small bowl and whisk to combine. Transfer 2 tablespoons of the sauce to a medium bowl, add the shrimp, and toss to combine; set the shrimp and remaining sauce aside.

Step 2

Make the stir-fry: Fill a large frying pan or flat-bottomed wok halfway with water, add a generous pinch of salt, and bring to a boil. Add the broccoli, cover, and cook, stirring halfway through, until crisp-tender, about 3 minutes total. Drain and set aside.

Step 3

Wipe the pan dry and heat over medium-high until a drop of water vaporizes immediately on contact. Drizzle in 1 tablespoon of the oil, add the shrimp, and spread into a single layer. Cook, undisturbed, until browned on the bottom, 2 to 3 minutes. Transfer to a plate or bowl; the shrimp will not be cooked through at this point.

Step 4

Reduce the heat to medium and add the remaining 1 tablespoon oil. Add the onion, season with salt, and cook, stirring, until softened and starting to brown, about 3 minutes. Add the ginger and garlic and stir-fry until fragrant, about 30 seconds.

Step 5

Return the broccoli and shrimp and any juices to the pan. Re-whisk the reserved sauce and add to the pan. Stir-fry until the shrimp is just cooked through and the sauce is glossy and coats everything in the pan, about 1 1/2 minutes. Top with the scallions and sesame seeds and serve over rice.