Heat a large skillet or wok over medium-high heat. Add 1 tablespoon of vegetable oil.
Pour the beaten eggs into the skillet, scrambling until just set. Remove from the pan and set aside.
Add the remaining oil to the skillet. Sauté onion until softened, about 2–3 minutes. Add garlic and cook until fragrant, about 30 seconds.
Stir in peas and carrots. Cook until warmed through and slightly tender.
Add the rice to the skillet, breaking up any clumps with a spatula. Cook for 3–4 minutes, allowing the rice to heat up and lightly crisp. The rice should not be soggy.
Pour in the soy sauce, oyster sauce (if using), and sesame oil. Stir well so every grain of rice is coated.
Add scrambled eggs and protein (if using) back into the skillet. Stir to combine, then toss in green onions.
Taste and season with salt and pepper as needed. Serve hot, garnished with extra green onions if desired.