We have tried different fish cake recipes that don't contain the usual bulking from potatoes, but to be honest they all seem to be missing something. On the whole they all seem to be dry.
Today we used the Crab cakes (using tinned salmon) from Everyday Paleo, but did not follow the recipe completely, as to make this dish would need a dozen eggs to make them for the four of us, as well as the tinned salmon, which does not makes them a sensible price.
I made up the fish cakes as the recipe says, but used a packet of hollandaise sauce - I'm not entirely happy about this, but I have to be realistic when I have to balance time against what my family are prepared to eat. They haven't chosen to eat paleo, and forcing them is not likely to make them what to do it.
I will continue looking for a moister mixture.