01 - In a small bowl, combine diced chicken, 1 tablespoon soy sauce, cornstarch, and 1 teaspoon vegetable oil. Marinate for 10 minutes.
02 - Whisk together eggs, milk, salt, and pepper until smooth.
03 - Heat 1 tablespoon vegetable oil in a large wok or skillet over medium-high heat. Stir-fry marinated chicken for 4 to 5 minutes until cooked through. Remove chicken and set aside.
04 - Add remaining 1 tablespoon vegetable oil to the pan. Sauté diced carrots and white parts of scallions for 2 to 3 minutes until slightly tender. Add frozen peas and cook for an additional 1 minute.
05 - Push vegetables to one side of the pan. Pour in egg mixture and scramble gently until just set.
06 - Add cooked rice, breaking up any clumps. Stir-fry everything together for 2 to 3 minutes to heat through evenly.
07 - Return cooked chicken to the pan. Add soy sauce, optional oyster sauce, and sesame oil. Toss well to evenly coat and heat all ingredients.
08 - Stir in green parts of scallions. Adjust seasoning with freshly ground black pepper if desired. Serve immediately while hot.