Step 1: In a bowl, toss the sliced beef with 1 tablespoon of soy sauce, 1 teaspoon of sesame oil, and 1 teaspoon of cornstarch. Let marinate for 10 minutes.
Step 2: Heat 1 tablespoon of vegetable oil in a wok or large skillet over high heat until smoking slightly.
Step 3: Add the beef in a single layer and sear for 1-2 minutes until browned. Remove beef from the pan and set aside.
Step 4: Add the remaining oil to the pan. Sauté the yellow onions for 3-4 minutes until softened and golden. Stir in garlic and ginger for 30 seconds.
Step 5: Add the cold rice to the pan, breaking up clumps. Add the remaining soy sauce and oyster sauce. Stir-fry for 2-3 minutes on high heat.
Step 6: Push rice to the side, pour in the beaten eggs, and scramble until set. Fold eggs and reserved beef back into the rice.
Step 7: Garnish with green onions and serve immediately.