Cut the beef into small diced, marinated in oil and soy sauce.
The yuba phlegm section is good. Cut the colored peppers. Cut the onion.
Heat the oil in a pot, stir fry the oil and yuba, then sauté the beef, fry until cooked on the other side, then fry all the ingredients, pour in the oyster sauce and season with salt.
Add the onions, if any, then mix well and serve in a pan.