To season the shrimp: In a bowl, add the shrimp and season with salt and white pepper. Mix and set aside.
To make the sauce: In a small bowl, whisk together the white pepper, soy sauce, and oyster sauce. Set aside.
To stir-fry the shrimp: In a wok over high heat, add 1 tablespoon of oil. Add the shrimp and stir-fry until pink, about 30 seconds. Remove and set aside.
To stir-fry the vegetables: In the same wok, add another tablespoon of oil. Add the onion, peas, carrots, and corn. Stir-fry until fragrant, about 30 seconds. Remove and set aside.
To cook the eggs and rice: Add the remaining tablespoon of oil. Pour in the beaten eggs and scramble until partially cooked. Add the overnight rice. Stir-fry for 1 minute, breaking up any clumps until each grain is separated.
To finish the fried rice: Return the shrimp and vegetables to the wok. Pour in the sauce and mix well to combine everything evenly. Top with scallions and serve hot.