Beef Stir-Fry with Bell Peppers and Black Pepper Sauce for Two

Combine 2 teaspoons water and baking soda in medium bowl. Add beef and toss to coat. Let sit at room temperature for 5 minutes.

Whisk ½ tablespoon soy sauce, ½ tablespoon sherry, ¾ teaspoon cornstarch, and ¼ teaspoon sugar together in small bowl. Add soy sauce mixture to beef, stir to coat, and let sit at room temperature for 15 to 30 minutes.

Whisk remaining 2 tablespoons water, remaining 1 tablespoon soy sauce, remaining 1 tablespoon sherry, remaining ¾ teaspoon cornstarch, remaining 1 teaspoon sugar, oyster sauce, vinegar, sesame oil, and pepper together in second bowl.

Heat 1 teaspoon vegetable oil in 12-inch nonstick skillet over high heat until just smoking. Add beef in single layer. Cook without stirring for 1 minute. Continue to cook, stirring occasionally, until spotty brown on both sides, about 1 minute longer. Transfer to bowl.

Return skillet to high heat, add 1 teaspoon vegetable oil, and heat until beginning to smoke. Add bell peppers and scallion greens and cook, stirring occasionally, until vegetables are spotty brown and crisp-tender, 2 to 3 minutes. Transfer vegetables to bowl with beef.

Return now-empty skillet to medium-high heat and add remaining 2 teaspoons vegetable oil, scallion whites, garlic, and ginger. Cook, stirring frequently, until lightly browned, 1 to 2 minutes. Return beef and vegetables to skillet and stir to combine.

Whisk sauce to recombine. Add to skillet and cook, stirring constantly, until sauce has thickened, about 30 seconds. Serve immediately.