Put the fish in a blender and stir it into the mud. Add salt, starch and egg white and mix well. Then add water (proportion about fish 3: water 1), stir it with chopsticks in one direction.
Prepare a large bowl of cold water and set aside. Grab a piece of fish paste with your hand and squeeze it up. Take the spoon with the other hand and take the fish ball and put it in cold water.
Heat a wok with the fish balls under high heat and cook until boiling. Turn the fire down and continue to cook a while. Soak the fish balls in the cold water for 3-5 minutes.
Heat another wok with oil, stir-fry garlic and onion until fragrant. Add the fish balls in the wok and stir-fry a few times. Add enough water until the fish balls are submerged.
Add the curry block and cook until boiling, add salt and cook under small heat for 5 minutes until the soup has thickened. Turn off the fire and wait 10 minutes. Serve.