If using day-old rice (see note), transfer to a medium bowl and break the rice up with your hands into individual grains.
Heat a wok over high heat until very lightly smoking. Add 3 tablespoon of the vegetable oil and swirl to coat. Reduce the heat to medium, pour the eggs into the center of the wok, and cook, swirling the wok, until the offs are puffy and golden brown around the edges, about 30 seconds. Use a spatula to release the eggs from the bottom of the wok, carefully flip, cook for another 15 seconds, swirling, then transfer the eggs to a bowl and set aside.
Return the empty wok to high heat until lightly smoking. Add the onion and carrot and cook, stirring and tossing constantly, until lightly softened and fragrant, about 1 minute. Transfer to the bowl with the egg.
Return the empty wok to high heat until lightly smoking. Add the remaining tablespoon oil and swirl to cat. Add the rice and cook, stirring and tossing, until the rice is pale brown and toasted and has a lightly chewy texture, about 3 minutes (see note). Add the scallions and garlic and story-fry until fragrant, about 30 seconds.
Return the vegetables and egg to the wok, using the spatula to break up the egg into small pieces as you toss everything together. Add the soy sauce, sesame oil, and peas.
