Bacalhau com Natas | Portuguese Creamy Baked Cod

Put the desalted cod in a pot with the milk and bay leaf. Heat until the surface barely shimmers, without bringing it to a boil, and cook for 10 minutes. Remove the fish and strain and reserve the milk for the béchamel. Once the fish is cool enough to handle, remove all the skin and bones and flake the flesh.

Peel the potatoes, cut them into 1 cm sticks, and pat them dry with paper towels. Heat the oil to 170°C / 340°F and fry the potatoes in batches until the edges are lightly golden; they do not need to be fully crisp, since they will soften in the oven. Lift them out with a slotted spoon and place them on a wire rack.

Heat the olive oil in a wide pan. Add the sliced onion and cook over low heat for 8 minutes until soft but not browned. Add the chopped garlic during the final 1 minute. Remove the pan from the heat, add the flaked cod, and toss gently; keep the flakes intact.

Melt the butter, add the flour, and whisk over low heat for 2 minutes, until the raw flour smell disappears. Gradually whisk in the warm milk used to poach the fish, and cook until thickened and smooth. Stir in the cream, nutmeg, and black pepper. Do not add salt; the cod and cheese are already salty.

Preheat the oven to 200°C / 390°F. Spread a thin layer of béchamel on the bottom of a baking dish, then layer half the fried potatoes, all the fish and onion mixture, and the remaining potatoes. Pour the rest of the béchamel on top and spread it into the corners with a spatula. Sprinkle the shredded cheese over the top.

Bake on the middle rack until the top is speckled golden and the sauce bubbles around the edges. If the top is still pale, turn on the broiler for the final 5 minutes and watch it closely. Let rest for 10 minutes before serving; portions will fall apart if scooped while hot.