Directions

1. Press out ginger juice (see note); whisk in soy sauce, vinegar, sugar, cornstarch, 1/4 teaspoon ground pepper, and 1 cup water; set sauce aside.
2. Season shrimp with salt and pepper. Heat 2 tablespoons oil in a large nonstick skillet over medium-high heat. Cook half the shrimp, turning once, until just opaque, 3 to 4 minutes; transfer to a plate. Add another tablespoon oil; repeat with remaining shrimp. Set shrimp aside.
3. Add remaining tablespoon oil to pan; cook bell peppers and white parts of scallions over medium-high heat, stirring, until crisp-tender, about 3 minutes.
4. Whisk reserved sauce; pour into pan, and bring to a boil. Cook, stirring, until thickened, 1 minute. Add shrimp and green parts of scallions; stir until coated with sauce, 30 seconds more. Serve immediately.