Heat ½ tablespoon of vegetable oil in a wok (or large nonstick frying pan) over medium-high heat. Add the beaten eggs and gently scramble with a rubber spatula until just softly set, 1-2 minutes. Transfer to a bowl and set aside.
Add 1 tablespoon of vegetable oil to the wok. Add the chicken, sautéing until lightly brown and fully cooked, about 7 minutes.
Heat another ½ tablespoon of oil in the wok, and add the onion, garlic, and salt. Cook, stirring occasionally, until the onion is tender, about 4-5 minutes.
Push the onion mixture to the sides of the wok. Add the remaining 1 tablespoon of vegetable oil and let it heat for a few seconds. Add the cold cooked rice, frozen peas and carrots, and soy sauce. Mix and stir-fry until the rice is heated through, about 3-4 minutes.
Remove from the heat and stir in scrambled eggs, green onions, and sesame oil. Serve immediately and enjoy!
