Toss 450g of ribeye in 1in / 2.5cm cubes with 1 tablespoon of oyster sauce, 1 tablespoon of soy sauce, 1 teaspoon of minced garlic, 2 tablespoons of garlic oil, and ½ teaspoon of sugar. Marinate for at least 1 hour.
Drain off the excess liquid and let the beef come to room temperature. Toss with 1 teaspoon of cornstarch, then brown on all sides in batches in a pan over high heat. Set aside.
Heat 1 tablespoon of vegetable oil and sauté ½ white onion and 1 bell pepper, both cut into large chunks, for about 2 minutes, until the onion is slightly translucent.
Return the beef, reduce the heat to medium-low, and stir for about 2 minutes. Toss in ½ scallion, cut into large pieces. Serve with the juice of 1 lime mixed with salt and pepper.
