In a mixing bowl mix the salmon, squid and mussels
Add the chopped herbs and onion, then add the egg and season and then combine with the mashed potato
Divide into 4 pieces and shape into fish cakes, using a palette knife to shape
To breadcrumb; dip the fishcake in the flour, then into egg wash and then finally into breadcrumbs
Heat a non-stick frying pan and cook gently until golden on both sides
Melt the butter over a gentle heat, add the flour and cook out for 3-4 minutes
Slowly add the milk and cook out for 3-4 minutes, until the right consistency, then add the cheese
Place cheese sauce on the plate, the fish cake on top and garnish with asparagus