Cod with Tomato Arguiñano Style: Homemade Recipe Step by Step

Arguiñano and cod with tomato: a television classic

If there's one dish that defines Karlos Arguiñano's cooking, it's one that combines simplicity, color, and flavor in a single bite. Cod with tomato perfectly meets all three requirements: it's one of those stews he has prepared dozens of times on his television show, always with minimal variations but with an unmovable constant — respect for the product.

Arguiñano's philosophy with this dish is transparent: ripe tomatoes, patiently poached onions, peppers that provide sweetness, and extra virgin olive oil that binds the entire sauce. No jarred sauces, no shortcuts. The result is a dish that smells like grandma's cooking and can be prepared in less than an hour.

This recipe is inspired by Karlos Arguiñano's style; it's not a literal transcription of his show. We have adapted the proportions to use premium Icelandic cod loins, a product whose firm texture and clean flavor elevate any home preparation to another level.

At Bacalalo, we have been selecting the best Icelandic cod at Mercat del Ninot in Barcelona since 1990. For Arguiñano-style cod with tomato, thick loins are the perfect choice: they remain whole during cooking and absorb the tomato flavor without falling apart.

Ingredients for Arguiñano-style cod with tomato

Serves 4

For the cod loins

• 4 Icelandic cod loins (about 200 g each, desalted)
• Flour for dusting
• Extra virgin olive oil

For the homemade tomato sauce

• 1 kg ripe tomatoes (pear or vine, very red)
• 2 large onions, thinly sliced
• 1 Italian green pepper, thinly sliced
• 1 red pepper, thinly sliced
• 4 cloves garlic, sliced
• 1 teaspoon sugar (to correct acidity)
• 100 ml extra virgin olive oil
• Salt and black pepper
• 1 bay leaf

Homemade tomato sauce: the soul of the dish

Arguiñano always says that "tomato sauce must be made with care and without rushing." That's the secret: poach the vegetables over low heat until they release all their natural sweetness before adding the tomato.

Step 1: Confit the onion and peppers

In a wide, shallow pot (like a rondeau or clay pot), heat the 100 ml of olive oil over medium-low heat. Add the thinly sliced onion and peppers. Cook, stirring occasionally for 20 minutes, until the onion is completely transparent and the peppers are tender. Do not raise the heat: slow confiting is the key to flavor.

When the vegetables are well poached, add the sliced garlic and bay leaf. Cook for 2 more minutes until the garlic is fragrant but not browned.

Step 2: Add the tomato

Grate the tomatoes with a coarse grater, discarding the skin. Pour the grated tomato over the confit vegetables. Increase the heat to medium and cook for 25-30 minutes, stirring every few minutes. The sauce should reduce until it thickens considerably — it should have body, not be watery.

If the tomato is too acidic, add the teaspoon of sugar. Arguiñano almost always does this: "sugar doesn't sweeten, it corrects," he says. Season with salt and black pepper to taste.

Step 3: Optional — blend or leave rustic

Here you have two options depending on your preference. You can blend the sauce to obtain a fine and silky tomato, or leave it with chunks for a more rustic texture. In Arguiñano's style, the rustic version is more common: the pepper strips and onion provide texture and presence to the dish.

Preparing the cod loins

If using dried cod, desalinate it in cold water in the refrigerator for 48 hours, changing the water every 8-10 hours. If you buy already desalted cod, you can skip this step. In any case, pat them very dry with kitchen paper before cooking.

Step 4: Sear the loins

Lightly flour the cod loins, shaking off any excess. In a wide pan with a generous amount of olive oil (Arguiñano never skimps on oil), sear the loins first on the skin side for 2 minutes. Flip them over and sear on the flesh side for 1 more minute. Don't try to cook them through — just sear them so they have a golden crust and don't fall apart in the sauce.

Remove the loins and set them aside on a plate. The inside should still be raw: it will finish cooking in the tomato sauce.

Step 5: Cook in the sauce

Place the seared loins over the tomato sauce in the pot. Cover and cook over low heat for 10-12 minutes. The loins should finish cooking slowly, absorbing the tomato flavor without losing their internal juiciness.

If the sauce is too thick, add a couple of tablespoons of water or fish broth. The cod will also release some juice that will enrich the sauce.

Final assembly and presentation

Arguiñano-style presentation is generous and colorful, without unnecessary flourishes. Serve directly from the pot or portion onto individual deep plates:

• A generous bed of tomato sauce at the bottom of the plate
• The cod loin on top, with the golden skin visible
• A drizzle of raw extra virgin olive oil over the top
• Sprinkled fresh chopped parsley
• A few strips of confit pepper decorating the loin

Serve with crusty bread to dip in the sauce. As Arguiñano says, "the best part is the bread with the sauce." Potato gratin or white rice are also perfect side dishes.

Arguiñano's tips for perfect cod with tomato

• Ripe tomatoes, always: The secret to a good tomato sauce is to use very ripe, red tomatoes. If it's not in season, canned plum tomatoes are a better option than bland greenhouse tomatoes.
• Confit, don't fry: Vegetables are poached over low heat, never fried. High heat caramelizes too quickly and produces bitterness instead of sweetness.
• Generous olive oil: Arguiñano never skimps on oil. Tomato sauce needs it to bind and have body. Oil is not a secondary ingredient, it's a protagonist.
• Sear before stewing: Lightly flouring and briefly searing the loins creates a protective layer that keeps the cod juicy inside the sauce. Without this step, the cod falls apart.
• Low heat to finish: The last 10-12 minutes of cooking should be over very low heat. The cod cooks with the residual heat of the sauce, not with aggressive boiling.
• Pinch of sugar: Don't be afraid to correct the acidity of the tomato with a little sugar. It's a classic technique that Arguiñano uses almost always.
• Rest before serving: Let the dish rest for 5 minutes off the heat before serving. The sauce settles, the flavors integrate, and the cod finishes cooking with the residual heat.

For an exceptional result, the quality of the cod makes all the difference. Bacalalo's Icelandic cod loins have the firm texture and clean flavor that this dish needs: they remain whole in the sauce and absorb all the tomato flavor without falling apart.

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