Fisherman's Pie

cod 50.0% , potato 29.0% , whole milk 10.5% , extra mature cheddar 5.3% , butter 2.6% , whipping cream 1.3% , mature cheddar 0.7% , onion 0.3% , potato 0.2% , corn flour 0.1% , rapeseed oil 0.0% , salt 0.0% , potato starch 0.0% , parsley 0.0% , mustard 0.0% , lemon juice 0.0% , yeast 0.0% , white pepper 0.0% , Colour 0.0%