Portuguese Baked Cod with Mayonnaise and Potatoes

Ingredients

• 900 g (2 lb), soaked for 24 hourssalt cod steaks
• 1 largeonion
• 150 ml (⅔ cup)mayonnaise
• 1 kg (2¼ lb)potatoes
• 50 ml (¼ cup)olive oil
• 1 teaspoonpepper
• 1 teaspoonoregano
• 50 g (1¾ oz)grated mozzarella or Parmesan cheese
• 2bay leaves
• to tastesalt
• as neededvegetable oil, for frying the potatoes

Instructions

1. 1

   Fry the potatoes

   Peel and wash the potatoes, then cut them into round slices. Lightly season with salt and fry in hot oil until lightly golden. Set them on a plate lined with paper towels to absorb excess oil.

2. 2

   Simmer the cod

   Meanwhile, put the cod steaks and two bay leaves in a saucepan of water. Bring to the boil over high heat, then lower the heat and cook for 6 to 7 minutes.

3. 3

   Flake the cod

   Turn off the heat and lift out the cod carefully with a slotted spoon. Leave it to cool slightly, remove the skin and bones, then flake the fish with a fork and set it aside.

4. 4

   Cook the onion

   Put the olive oil and chopped onion in a saucepan. Stir with a wooden spoon and sauté over low heat, stirring occasionally, until the onion starts to turn slightly golden brown. Add the flaked cod, pepper and oregano; stir well and cook for about 5 minutes, stirring occasionally.

5. 5

   Heat the oven

   Preheat the oven to 180°C (350°F).

6. 6

   Layer the dish

   In a baking dish, make a layer of potatoes, followed by a layer of cod and another layer of potatoes. Spread the mayonnaise evenly over the top and scatter over the grated cheese.

7. 7

   Bake until golden

   Bake for 25 to 30 minutes, until the top is golden and bubbling.

What is Portuguese baked cod?

This is a layered cod and potato bake inspired by Portuguese home cooking, where salt cod is a familiar ingredient. Here, the fish is simmered, flaked and cooked with onion before being baked beneath potatoes, mayonnaise and cheese.

The separate layers make this version satisfying and easy to portion: the fish stays tender while the topping turns golden and bubbling.

Nutrition and macros by portion

The nutrition label shows one serving as written: 750 calories, 42g protein, 45g carbs, 44g fat.

The potatoes provide most of the carbohydrate, while the mayonnaise and frying and olive oils account for much of the fat. Cod is the main source of protein, with a smaller contribution from the cheese. Serve a portion with salad or green vegetables for a fresh contrast and a more balanced plate.

Choosing and preparing the cod

Salt cod: soak the steaks for 24 hours before cooking, as specified in the recipe. The soaking is part of the preparation, so allow for it in addition to the stated 70-minute total time.

Bones and skin: once the fish has cooled enough to handle, remove both carefully before flaking it. Check the flakes as you work, since small bones can be easy to miss.

Frying the potatoes

Even slices: cut the potatoes into rounds of similar thickness so they cook at a similar rate.

Light golden colour: fry them only until lightly golden, then drain on paper towels. They will bake again in the oven, so they do not need to be deeply browned at this stage.

Building flavour in the fish

Soft onion: cook it gently in the olive oil until it begins to turn slightly golden. Keeping the heat low helps the onion soften without rushing the step.

Seasoning: add the pepper and oregano with the flaked cod, then cook the mixture for about 5 minutes. Salt cod can already be salty, so taste before adding extra salt.

Layering for a good finish

Potato and cod: follow the stated order of potatoes, cod, then another layer of potatoes. Spread the mayonnaise across the top and finish with the grated cheese.

Cheese choice: mozzarella gives a milder, stretchy topping, while Parmesan brings a more savoury, pronounced flavour.

How to tell when it is ready

Oven time: bake at 180°C for 25 to 30 minutes. The recipe’s cue is a golden, bubbling top.

Rest briefly after baking so the layers settle and the portions are easier to lift from the dish.

What to serve alongside

Fresh contrast: serve with a simple green salad or lightly dressed leafy vegetables to balance the creamy topping.

For a fuller meal, add steamed green vegetables. The bake already includes potatoes, so another starchy side is usually unnecessary.

Recipe notes & tips

• Soak the salt cod for the full 24 hours before starting the recipe.
• Drain the fried potato slices on paper towels before layering.
• Remove skin and bones after simmering, while the cod is cool enough to handle.
• Taste the cod mixture before adding salt, since salt cod can retain salt after soaking.
• Use a baking dish that leaves room for all three layers and the topping.
• Watch for a golden, bubbling surface as the cue to take the dish out of the oven.

Variations

• Choose Parmesan: use it instead of mozzarella for a sharper, more savoury topping.
• Choose mozzarella: use it for a milder cheese layer.
• Add a green side: serve with salad or steamed green vegetables for freshness.
• Adjust the oregano: use a little less for a subtler herbal flavour.
• Cut smaller portions: serve the bake with extra salad when you want a lighter-feeling plate.

Common mistakes to avoid

• Skipping the soak: soak the salt cod for 24 hours as directed before cooking.
• Over-frying the potatoes: stop when they are lightly golden, since they will bake again.
• Leaving bones behind: check the cod carefully as you remove the skin and bones.
• Adding salt automatically: taste the cod mixture first because salt cod may still be salty.
• Baking by time alone: check that the topping is golden and bubbling within the 25 to 30 minute bake.

How to store

Refrigerate leftovers in a covered container and eat within 2 days. Reheat in an oven until hot throughout; the topping may soften after storage.

Frequently asked questions