Heat the vegetable oil in a wok or large skillet over medium-high heat. Once hot, add the chicken pieces and cook until they are browned and cooked through, about 5-7 minutes. Stir frequently to ensure even cooking.
Add the diced onion to the pan and sauté for an additional 2-3 minutes until the onion becomes translucent. Then, add the thawed peas and carrots, stirring until they are heated through.
Push the chicken and vegetables to one side of the pan. In the empty space, pour in the lightly beaten eggs. Stir gently until the eggs are scrambled and fully cooked, then mix everything together.
Add the cooked rice to the pan, breaking up any clumps. Pour in the sesame oil and the soy sauce, tossing everything together until the rice is evenly coated and heated through, about 3-5 minutes.
Taste your fried rice and adjust the seasoning as needed. Add more soy sauce if you prefer a stronger flavor.
Remove the pan from heat and serve your Better than Takeout Chicken Fried Rice hot, garnished with sliced green onions for an extra touch of freshness.