Cut the beans and stalk the potatoes (if you don't burn them immediately, soak them in water). Wash the potatoes and cut them together.
Open the medium fire, first dry the wok, then pour a small amount of oil and then add the beans and potatoes to stir fry. When the color of the bean turns green, add the soy sauce and put it into the water bowl of the big bowl and half bowl. Cook the lid for a while
When you are good, put in sugar and salt and cook for a while.