A true Chinese cook doesn't really have a recipe that he follows as a lot depends on the feel of the ingredients you are working with at the time. In general Dad debones 2 mackerel cutlets and chops with Chinese meat cleaver on a wooden chopping board (don't even think about using a food processor, it needs to be done the traditional Chinese way for authenticity). Add water to the paste with a couple of teaspoons of salt and mix until the the paste is smooth and thick (if you can stand a spoon in the mixture, it's ready).
Cut the beancurd puff in half diagonally, make a slit and stuff with the fish paste.
Add a little oil in a wok and using super long wooden chopsticks (again to add to the authenticity), cook the beancurd puff, fish side down, until lightly brown.