Season the diced chicken breast with salt and white pepper. Heat 1 tablespoon vegetable oil in a large wok or skillet over high heat. Add the chicken and stir-fry for 5 to 6 minutes until golden and cooked through. Transfer to a plate.
Add the remaining 1 tablespoon vegetable oil to the wok. Add the frozen peas and carrots and stir-fry for 2 minutes until thawed and heated through. Add the minced garlic and cook for 30 seconds.
Push the vegetables to the side of the wok. Pour the beaten eggs into the empty side and scramble them, breaking them into small pieces as they cook.
Add the cold rice to the wok and toss everything together. Stir-fry for 3 to 4 minutes, pressing the rice against the wok to get some crispy bits. The cold rice will separate nicely and get a great texture.
Return the chicken to the wok. Pour the soy sauce and sesame oil over everything and toss to combine. Stir-fry for another minute.
Remove from heat and top with sliced green onions. Serve immediately while the rice is hot and slightly crispy.