First, prepare the batter: butter chopped in small cubes and place in a large blender or food processor, add the crushed walnuts, breadcrumbs (I have them ready dried, out of the ordinary bran bread), lemon zest, 2/3 of cheese, salt, a little pepper. All is crushed into uniform crumbs.

Fillet to check for bones, remove them with tweezers, remove the skin and cut into portions. Lay fillets on a lightly greased olive oil baking pan, down the side, which was leather. Season with salt and pepper and on top "hide" the battered smooth dense layer. Remove the pan in the refrigerator for 20 minutes to allow the breading stuck.

Preheat the oven to 200 degrees. Each piece sprinkle with remaining Parmesan and bake for 20-25 minutes until Golden brown.