To marinate the shrimp: In a mixing bowl, season the shrimp with salt and white pepper. Mix the cornstarch with water to make a slurry, then add it to the shrimp and mix well.
To prepare the egg mixture: In another bowl, whisk together the eggs, salt, and white pepper. Mix the cornstarch with water to make a slurry, then add it to the eggs. Whisk until combined and stir in the scallions.
To stir-fry the shrimp: In a pan over high heat, add 1 tablespoon of cooking oil. Add the shrimp and stir-fry for about 1 minute, until they begin to turn pink and are nearly cooked through. Transfer the shrimp directly to the egg mixture to distribute them evenly and allow them to finish cooking gently with the eggs.
To cook the shrimp and eggs: Reduce the heat to medium and add the remaining 2 tablespoons of cooking oil. Pour in the shrimp and egg mixture. As the edges begin to set, gently push the eggs from side to side without flipping, creating soft, fluffy folds. Cook until the eggs are softly set and the shrimp are fully cooked.
To serve: Slide the shrimp and eggs onto a plate and serve immediately with steamed rice or congee.