This Portuguese-inspired baked fresh cod pairs flaky fish with tender potatoes, slow-sweetened onions, olives, and hard-cooked eggs. It borrows the comforting flavors of Portuguese bacalhau dishes while using fresh cod, so it makes a savory, satisfying meal without the soaking and desalting needed for traditional salt cod.
Ingredients
- 1¾ lb fresh cod fillets (790 g), skin removed if desired, cut into 4 portions
- 1¾ lb waxy potatoes (790 g), such as Yukon Gold or red potatoes
- 2 medium yellow onions (about 300 g), thinly sliced
- ⅓ cup extra-virgin olive oil (80 ml), divided
- 3 garlic cloves (9 g), finely chopped
- 1 dried bay leaf (about 0.2 g)
- 1 tsp fine salt (6 g), plus more as needed
- ¼ tsp freshly ground black pepper (0.5 g)
- 4 large eggs (about 200 g without shells)
- ½ cup pitted Portuguese or other briny black olives (75 g), halved if large
- ¼ cup chopped flat-leaf parsley (15 g)
- 1 tbsp lemon juice (15 ml), optional, for serving
Instructions
- Heat the oven and prepare the potatoes. Heat the oven to 400°F (200°C). Scrub the potatoes and cut them into roughly ½-inch (1.3 cm) slices; there is no need to peel them unless you prefer. Put them in a large pot, cover with cold water by about 1 inch (2.5 cm), and add a generous pinch of salt. Bring to a boil, then simmer for 10–12 minutes, until the slices are just tender when pierced but still hold their shape. Drain carefully. They will finish cooking in the oven, so avoid boiling them until soft or they may break apart in the casserole.
- Cook the eggs while the potatoes simmer. Place the eggs in a small saucepan and cover with cold water by 1 inch (2.5 cm). Bring the water to a boil, cover the pan, turn off the heat, and leave the eggs for 10–12 minutes, until the yolks and whites are firm. Transfer them to cold water to cool, then peel and cut into quarters. If you prefer, cook the eggs after the potatoes in the same pot; the timing is flexible as long as they are fully cooked.
- Soften the onions. While the potatoes cook, warm ¼ cup (60 ml) of the olive oil in a wide skillet over medium-low heat. Add the sliced onions, garlic, bay leaf, half of the salt, and the black pepper. Cook for 10–12 minutes, stirring often, until the onions are soft and translucent with a little golden color. Keep the heat moderate: browned, crisp onions can taste bitter and will not give the casserole its mellow, savory base. Remove the bay leaf before assembling.
- Layer the casserole. Spread about half of the drained potatoes in a shallow 9-by-13-inch (23-by-33 cm) baking dish. Spoon half the onion mixture over them, then arrange the remaining potatoes and onions on top. Set the cod portions across the surface, leaving a little space between pieces. Drizzle with the remaining ¼ cup (60 ml) olive oil and season the fish with the remaining salt. Scatter the olives over the dish. The fish does not need to be buried under the potatoes; keeping it exposed helps it cook evenly.
- Bake until the cod is safely cooked. Bake uncovered for 18–22 minutes, depending on the thickness of the fillets. Check the thickest part of a portion with a food thermometer: USDA FSIS lists 145°F (63°C) as the safe minimum internal temperature for fish. At that temperature, cod should look opaque and separate into moist flakes. If it has not reached 145°F (63°C), return the dish to the oven and check again after a few minutes. Avoid relying on the clock alone, since thin tail pieces cook faster than thick center cuts.
- Finish and serve. Scatter the parsley and egg quarters over the hot casserole. Add the optional lemon juice just before serving, tasting first because the olives and salted cooking water already contribute salt. Let the dish stand for about 5 minutes so the juices settle, then bring the baking dish to the table and serve warm.
Tips
- Choose the right cod. Fresh cod should smell mild and clean, not strongly fishy, and its flesh should look moist rather than dried at the edges. Frozen cod works too: thaw it overnight in the refrigerator, then pat it dry before baking. Excess surface water can dilute the olive oil and onion flavors.
- Keep the potatoes intact. Waxy potatoes hold their shape better than very starchy baking potatoes. Stop the parboil when a knife meets slight resistance in the center. If the slices are already falling apart, drain them gently and layer them with a light hand.
- Adjust the salt for the olives. Portuguese-style briny black olives can be salty, and some olives are saltier than others. Start with the listed salt, taste an olive, and add more only after baking if the dish needs it. Kalamata olives are an easy substitute; they bring a fruitier, more assertive flavor.
- Do not overcook the fish. Cod continues cooking briefly from residual heat after it comes out of the oven. Check the thickest piece early if your fillets are thin, and remove the casserole once the fish reaches 145°F (63°C). A thermometer is more reliable than judging flakiness alone.
Serving Suggestions
Serve this casserole as the centerpiece of a simple meal. A crisp green salad with a vinegar-based dressing balances the soft potatoes and olive oil, while steamed green beans, sautéed greens, or roasted peppers add another vegetable without competing with the cod. Crusty bread is useful for catching the savory oil and onion juices left in the serving dish.
For a Portuguese-inspired table, offer lemon wedges, extra parsley, and a small bowl of olives. The recipe is filling enough to serve on its own, but you can stretch it to a larger meal with soup or a modest vegetable side. If serving guests, portion the fish carefully and spoon the potato-and-onion layers alongside it so each plate gets some olives and egg as well.
Variations
This is a fresh-cod adaptation, not a claim to be the one definitive version of a Portuguese bacalhau recipe. In Portugal, many celebrated cod dishes use bacalhau—salted and dried cod—which is typically soaked and rinsed to remove excess salt before cooking. Fresh cod has a gentler flavor and a softer, juicier texture, and it does not need soaking. If you substitute rehydrated salt cod, follow reliable preparation instructions for desalting and reduce or omit the added salt; its texture and seasoning will be noticeably different.
If cod is unavailable, use haddock or pollock in the same amount, checking the thickest portion for the same safe internal temperature. For a richer onion layer, add one thinly sliced red bell pepper and cook it with the onions until soft. A small pinch of red pepper flakes or a few drops of piri-piri sauce adds gentle heat, while chopped cilantro can replace some or all of the parsley for a brighter finish.
You can also make the casserole without eggs, or serve the eggs on the side for diners who prefer them separately. If you want a little more crispness, arrange the cooked potatoes in a single top layer and drizzle them lightly with oil; they will brown modestly at 400°F (200°C), though this is a tender baked casserole rather than a crisp roast-potato dish. Avoid adding extra liquid: the fish releases moisture as it cooks.
Storage and Reheating
Refrigerate leftovers within 2 hours of cooking, transferring them to a shallow airtight container once they have stopped steaming heavily. The cooked cod, potatoes, and eggs keep for 3–4 days in the refrigerator. For the best texture, store portions rather than repeatedly warming and cooling the whole casserole. The fish may become firmer after chilling, which is normal.
Reheat a portion covered in a 325°F (165°C) oven until hot throughout, or microwave it in short intervals with a cover to limit drying. Stir or rotate the potatoes if using a microwave, and check that leftovers reach 165°F (74°C), the USDA FSIS reheating temperature. Add a teaspoon of water or olive oil if the potatoes seem dry. You can freeze portions for up to 2 months for best quality, although the potatoes may soften and the cod may lose some of its delicate texture. Thaw overnight in the refrigerator and reheat promptly; do not leave cooked fish at room temperature for extended storage.
Frequently Asked Questions
Can I use frozen cod?
Yes. Thaw it completely in the refrigerator, ideally overnight, and blot the fillets dry before assembling the dish. If the portions are especially thick, they may need a few extra minutes in the oven, but check each piece with a thermometer rather than assuming all fillets cook at the same rate.
Is fresh cod the same as bacalhau?
No. Bacalhau usually refers to salted and dried cod that has been rehydrated before cooking. Fresh cod is unsalted and has a milder flavor and moister texture. This recipe takes inspiration from Portuguese cod-and-potato combinations but is designed specifically for fresh fish, so it skips the soaking and desalting step.
Can I prepare the casserole ahead?
You can boil the potatoes, cook and peel the eggs, and soften the onions up to a day ahead; refrigerate each component separately. Assemble the casserole shortly before baking so the raw fish stays chilled and the potatoes do not absorb too much oil. A cold dish may need a few additional minutes in the oven, so use the temperature check to judge doneness.
What should I do if my cod fillets are different sizes?
Arrange pieces of similar thickness together and begin checking the thinner ones early. Remove any portion that has reached 145°F (63°C) while thicker pieces finish, then cover the cooked fish loosely to keep it warm. Avoid cutting every piece to the same small size, since thinner pieces can dry out before the potatoes are hot.
Can I make this without olives?
Yes. Leave them out and add a little extra parsley and lemon at the table, or use a few capers for a different briny note. Capers are often quite salty, so rinse them and taste before adding more salt. The casserole will still have plenty of flavor from the softened onions, garlic, and olive oil.
Related
- Portuguese Ciri-Ciri Recipe: Crisp, Golden Fried Bites
- Portuguese Piri Piri Marinade for Chicken
- Portuguese Piri Piri Chicken Skewers with Marinade
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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes
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