Peel and cut the carrots in half lengthwise, then thinly slice them.
Chop the celery thinly into half moons and set them aside.
In a large frying pan or a wok heat the oil over medium heat and add the onions. Fry them for around a minute and add the garlic. Fry this for around a minute as well.
Then add the thinly sliced pieces of bavette cut into 10 cm strips, season with black pepper, and fry for 4 minutes.
While the bavette is frying, mix the oyster sauce, soy sauce, ketchup and MSG in a bowl. Set aside. In another bowl, mix cornstarch with the water in another bowl and also set aside as well.
Once the bavette has browned, add the carrots and celery and stir well, mixing well. Cook them for around 3 to 5 minutes. Do not overcook them, the vegetables need to remain slightly crunchy.
Next, add the bean sprouts, followed by the sauce and cornstarch. Mix well.
Continue stirring and mixing until the bean sprouts are slightly cooked and everything is coated with the sauce. Add the Árbol chillies whole or cut them into small pieces for more heat. Sprinkle more MSG and mix. Turn the heat off and serve it with white rice.