Whisk egg with 1 teaspoon oil in a small dish then set aside.
Heat another teaspoon oil in a large wok or skillet over high heat. Season chicken with white pepper and salt then add to hot wok and stir fry until cooked through. Remove to a plate then set aside.
Heat remaining teaspoon oil in the wok then add frozen vegetables. Stir fry until tender, 1-2 minutes, then add garlic and stir fry for 30 more seconds being careful not to let it burn.
Push vegetables to the side of the wok then add egg and sesame oil mixture into the center and scramble.
Add butter then, once melted, add cooked chicken and rice and then toss to combine.
Drizzle in tamari, toss to combine, then serve.
