To remove the salt from the cod, place it in cold water for 24 hours, skin side up. Change the water a few times.

Cook the cod in the milk over medium heat for about about 10 minutes. Remove the cod with a slotted spoon once cooked through and set aside to cool enough to handle. Strain the milk with a sieve and set aside.

Fry the potatoes in a deep fryer over medium-low heat. If the heat is maxed the potatoes will burn on the outside but still be raw on the inside so they need to fry low and slow. Remove onto a plate lined with kitchen roll.

Once the cod is cooled enough to handle, using your fingers flake the fish, removing any fish bones as you go. Set aside when done.

To make the sauce, heat the butter over low-medium heat and whisk in the flour in. Cook for 5 minutes stirring regularly.

Mix the double cream with the cooled milk and slowly bit by bit stir into the floured mixture until it thickens. Season with salt, pepper and nutmeg. Continue until the milk has all been added and the mixture is smooth and creamy.

Next heat olive oil over medium heat and fry the bay leaves and onions until soft and translucent. Add the garlic and fry for another minute or less.

Add the flaked code and potatoes and fry for 3-5 minutes. Mix in well 2/3 of the sauce.

Transfer to an ovenproof dish. Top with the remaining sauce. Sprinkle with grated cheese and place in a preheated oven until the cheese has melted and the top is lightly browned (about 20 minutes).

Allow to rest for 10 minutes before serving.