Portuguese Creamy Cod

Ingredients

• 2 cod fillets
• 400 ml milk, whole or semi-skimmed
• 0.5 onion
• 0.5 tbsp flour
• 500 g potatoes
• 150 ml fresh cream
• grated cheese (mozzarella)
• ground nutmeg
• olive oil
• salt
• pepper

Method

Poach the cod in milk to cook the fish gently and build a sauce base simultaneously. Heat 400 ml whole milk in a saucepan until it steams — not a rolling boil, which breaks down the delicate protein structure. Add the cod fillets and maintain a bare simmer for 10–12 minutes. The flesh should flake easily when pressed with a fork and turn opaque throughout. Remove the fish to a plate and reserve the milk; don't discard it. This fish-cookery approach means your sauce is already infused with the fish's flavour.

Whilst the cod cooks, ready the aromatics and thickener. Slice half an onion thinly and fry in olive oil over medium heat until the edges turn amber and the flesh softens — roughly 4–5 minutes. This is where the Maillard reaction deepens the sweetness. Sprinkle the flour over the onions and stir continuously for 60 seconds to cook out the raw starch taste. Pour in the reserved milk gradually, whisking to prevent lumps. The flour acts as a thickening agent through the starch granules absorbing liquid and swelling. Simmer on low heat for 5 minutes, stirring occasionally, until the sauce coats the back of a spoon. Shred the cooled cod into bite-sized flakes and fold into the sauce.

Cut potatoes into roughly 1 cm cubes — uniform sizing matters here so they cook evenly. Heat a shallow layer of oil in a frying pan over medium-high heat and pan-frying|pan-fry the potatoes for 8–10 minutes, turning every 2–3 minutes, until the edges are golden and the interiors are just tender when pierced. They should resist the fork slightly; they'll finish cooking in the oven.

Transfer the cod mixture and potatoes to an oiled baking tray and fold together gently. Season with salt, pepper, and nutmeg — use sparingly with the nutmeg; a quarter-teaspoon is enough for this quantity. Pour 150 ml fresh cream evenly over the surface and scatter grated mozzarella across the top. Bake at 200°C for 18–22 minutes until the cheese colours to golden-brown and the cream bubbles at the edges. The dish is ready when the surface has developed a light crust and no longer looks wet.