Make the Fried Rice: Heat 1 tablespoon of oil in a large pan or wok over medium heat. Add the diced carrots and green beans (or peas), sautéing until tender, about 4-5 minutes. Next, add the day-old cooked basmati rice to the pan, breaking up any clumps. Season with salt, pepper, and garlic powder (if using) for extra flavor. Stir in the chopped green onions and cook for another 2-3 minutes, tossing until the rice is hot and fluffy. Set aside once done.
Cook the Beef Stir-Fry: Heat 1 tablespoon of oil in a skillet or wok over medium-high heat. Add the beef strips in batches, searing them until browned on all sides. This should take about 2-3 minutes. Remove the beef from the skillet and set it aside. In the same skillet, add the sliced onion and bell pepper. Cook until they are softened and have a slight char, about 4-5 minutes. Add the minced garlic and cook for an additional minute until fragrant. Stir in the soy sauce, oyster sauce, and black pepper, and cook for 2 minutes more. Mix the cornstarch with ¼ cup of water to create a slurry, then add this to the skillet, stirring constantly. Let the sauce simmer for a couple of minutes until it thickens and coats the beef and vegetables.
Assemble: To serve, plate a portion of the vegetable fried rice on one side of the plate and scoop the saucy beef stir-fry next to it. The tender beef and crisp vegetables will complement the flavorful rice perfectly.
