Pat chicken cubes dry with paper towels and toss in a bowl with cornstarch, salt, and pepper until evenly coated.
Heat 1 tablespoon of avocado oil in a wok or large carbon steel skillet over high heat until shimmering.
Add the chicken in a single layer and sear for 3-4 minutes per side until crispy and the internal temperature reaches 165°F (74°C). Remove chicken and set aside.
Add the remaining 1 tablespoon of oil to the wok. Add minced garlic and sauté for 30 seconds until fragrant.
Incorporate the chilled rice into the wok, pressing down with a spatula to break up clumps. Fry for 4-5 minutes until the grains are toasted.
Push the rice to the perimeter of the wok. Pour the whisked whole eggs and egg whites into the center. Scramble until 80% set, then fold into the rice.
Add the frozen peas and carrots, soy sauce, and oyster sauce. Toss continuously for 2 minutes.
Return the crispy chicken to the wok. Drizzle with sesame oil and add green onions.
Perform a final high-heat toss for 60 seconds to emulsify sauces and serve immediately.