Prepare sauce by combining oyster (flavor) sauce, soy sauce, sesame oil, and white or black pepper in a small bowl.
Cube steak into 1-inch cubes. Add half of the sauce prepared to steak cubes, and save the other half for later. Mixed sauce with steak. Set aside and marinate for ~30 minutes.
Mince garlic and dice onion. Fluff cooked rice to remove clumps. Set all ingredients needed for stir fry by stove - egg, mixed vegetables, rice, garlic, onion, marinated steak, and sauce.
Add vegetable oil to wok or skillet and heat on high heat. When wok/skillet is heated, add steaks to wok/skillet and cook for 2-4 minutes, or to desired doneness. Avoid over-cooking. Remove and set aside.
Add vegetable oil to wok/skillet again and heat on high heat. When wok/skillet is heated, add minced garlic and onion, stir continuously, cook for 30-60 seconds or until onions turn slightly golden brown. Add rice to wok, stir continuously, cook for 1-2 minutes. Add mixed vegetables, stir, cook for 1 minute. Add sauce that you set side earlier and the rest of the steak, stir and cook for another minute.
Push fried rice to one side of the wok, and crack an egg directly to the wok/skillet (where there is no fried rice). Break the yolk and mesh up egg using turner/spatula. Then cover the slightly raw egg with the fried rice (pile the rice on top of the still-runny egg). Let it sit for a few seconds, then stir to combine egg with rice. Cook for a minute.
Remove fried rice from heat. Garnish with scallions (if desire).
Serve and enjoy!
Note that all measurement, including cup measurement for cooked rice, is based on US measurement.