Fish cakes

Cut hake fillets into two or three pieces. Pack tightly into a small saucepan.
Stir 5 ml salt into 500 ml boiling water. Pour over fish to just cover and simmer for 15 minutes.
Remove from heat and leave fish in water until cool enough to handle. Carefully remove fish from cooking liquid.
Lifting the edge of the skin with a knife, gently pull away all skin, using your fingers. Break fish into large flakes, taking care to remove all bones as you do so.
Put fish into a bowl and, using a fork, mash into fine flakes. Put to one side.
Wash and peel potatoes, then place them in a pot of cold water, bring to the boil and simmer for 20 minutes. Drain and mash with 25 g of the butter.
Put trout into a food processor and blend with 40 g butter until pale and smooth. Set aside.
Separate one egg. Reserve white and put yolk into a bowl.
Melt remaining butter and whisk into egg yolk a little at a time until mixture is thick and smooth.
In a large bowl, mix together flaked fish and mashed potato. Add smoked trout mixture, egg and butter sauce, chopped chives, tarragon and seasoning.
Mix well but do not overbeat, as mixture will become too smooth.
Divide mixture into 12 equal portions.
Shape into balls, and gently flatten with the palm of your hand so they resemble medium-sized cakes.
Put flour into bowl. Beat reserve egg white with a whole egg.
Place breadcrumbs in a separate bowl. Roll each fishcake in flour, then beaten egg and finally coat evenly in breadcrumbs.
Heat oil in a large, heavy-based saucepan. Gently fry cakes for 4 to 5 minutes or until golden. Drain on kitchen paper.
Serve hot with a crispy mixed leaf salad and a sauce tartare.