Fluff the cold rice with your hands to separate the grains.
Heat a large skillet or wok over medium-high. Add a little oil and scramble the eggs until just set. Transfer to a plate.
Add remaining oil. Sear the chicken until browned and cooked through, 4 to 5 minutes. Season with salt and pepper. Move to the plate.
Sauté the onion until translucent. Stir in garlic and ginger and cook 30 seconds until fragrant.
Add peas and carrots. Cook, stirring, until heated through.
Add the rice. Stir-fry, breaking up clumps, until hot and lightly toasted.
Return chicken and eggs. Pour in soy sauce, oyster sauce, and rice vinegar. Toss until evenly coated.
Finish with sesame oil and green onions. Taste and adjust seasoning, then serve hot.