Heat 1 tablespoon of vegetable oil in a large pan or wok over high heat.
Add the sliced steak, season with salt and pepper, and cook until browned for 2 to 3 minutes. Remove and set aside.
In the same pan, cook the shrimp for 2 to 3 minutes until pink and cooked through. Remove and set aside.
Add a little oil if needed, pour in the beaten eggs, scramble quickly, then remove and set aside.
Add the remaining oil to the pan, sauté minced garlic for about 30 seconds.
Add mixed vegetables and cook for 2 to 3 minutes.
Add the cooked rice, breaking up any clumps, and stir-fry.
Return the steak, shrimp, and scrambled eggs to the pan, then add soy sauce, oyster sauce, and sesame oil.
Stir-fry everything together for 2 to 3 minutes until well combined.
Stir in chopped green onions, taste, and adjust seasoning if needed. Serve hot.