Pork ribs should be blanched first and then fried. Blanching is to remove residual blood.
Pork ribs contain a lot of blood. If they are stewed directly, the blood will run into the soup, making the color black and producing a fishy smell.
Don't stew ribs and big bones directly. If you want to remove blood, the method is to soak them in salt water. When the color turns white, you say that the blood is almost soaked.