Bacalao a la Vizcaína with Choricero Pepper Sauce

Why You’ll Love This Recipe

• Authentic Basque flavor from choricero peppers and slow-sweet onions.
• Silky, brick-red sauce that emulsifies beautifully with olive oil.
• Reliable desalting, temperatures, and timings for perfectly flaky fish.
• Make-ahead friendly: the sauce can be prepared in advance.

Grocery List

• Produce: Yellow onions, garlic, flat-leaf parsley, bay leaf
• Dairy: None
• Pantry: Salt cod (bacalao), dried choricero peppers or jarred choricero paste, extra-virgin olive oil, dry white wine, fish stock or water, fine sea salt, black pepper, sugar (optional)

Full Ingredients

For the Salt Cod

• 1.5 lb (680 g) skin-on salt cod (bacalao), preferably thick loins or center-cut fillets
• Cold water for soaking (about 2–3 quarts/2–3 liters to start; you will change it 3–4 times)

For the Choricero Pepper Purée

• 8 dried choricero peppers, stems and seeds removed, or 6 tbsp jarred choricero pepper paste
• 2 cups (480 ml) very hot water, for soaking the dried peppers

For the Vizcaína Sauce

• 3 large yellow onions (about 700 g), thinly sliced (pole-to-pole)
• 6 garlic cloves, thinly sliced
• 1 bay leaf
• 1/2 cup (120 ml) extra-virgin olive oil
• 1/4 tsp fine sea salt (for the onions only; season gently overall)
• 1/4 cup (60 ml) dry white wine (optional)
• 1 cup (240 ml) unsalted fish stock or water, plus 1/4–1/2 cup (60–120 ml) more as needed to adjust thickness

To Finish

• 1/4 cup (60 ml) extra-virgin olive oil
• Freshly ground black pepper, to taste
• Pinch of sugar, optional (balances bitterness if needed)
• 2 tbsp finely chopped flat-leaf parsley

Step-by-Step Instructions

Step 1: Desalt the cod

Rinse the salt cod under cold running water to remove surface salt. Place in a large bowl or container, cover with plenty of cold water (at least 2 inches/5 cm above the fish), and refrigerate for 36 hours, changing the water 3–4 times. After desalting, pat dry and cut into 4 even pieces. Tip: to check seasoning, cook and taste a small flake; it should be pleasantly seasoned, not salty.

Step 2: Prep the choricero peppers

Place dried choricero peppers in a bowl and cover with very hot water. Weight them down with a small plate to keep submerged and soak 30–40 minutes until fully pliable. Pull off stems and scrape out seeds. Using a spoon, scrape the soft red pulp from the inside of each pepper; discard skins. You should have about 6 tablespoons of pulp. If using jarred choricero paste, measure 6 tablespoons and set aside.

Step 3: Slowly sweeten the onions

In a wide, heavy skillet or shallow saucepan, warm 1/2 cup (120 ml) olive oil over medium-low heat. Add the onions, bay leaf, and 1/4 tsp salt. Cook gently, stirring occasionally, 25–30 minutes until the onions are soft, translucent, and lightly golden—no browning or crisp edges. Stir in the garlic and cook 2–3 minutes more until fragrant.

Step 4: Build the Vizcaína base

Add the choricero pepper pulp to the onions and stir to coat. If using, pour in the white wine and simmer 2 minutes to cook off alcohol. Add 1 cup (240 ml) stock or water, bring to a gentle simmer, then cook 8–10 minutes to meld flavors. The sauce should be loose but not watery.

Step 5: Purée and adjust

Fish out the bay leaf. Blend the sauce until perfectly smooth and silky using an immersion blender (or transfer to a blender and purée, venting the lid). If needed, add 1/4–1/2 cup (60–120 ml) more stock or water for a pourable, velvety consistency. Taste and adjust: a twist of black pepper and, only if needed, a tiny pinch of sugar to balance. Return the sauce to the pan over low heat.

Step 6: Cook the cod gently in the sauce

Nestle the cod pieces skin-side down into the sauce, spooning sauce over to mostly cover. Keep the heat very low—just a tremble of bubbles (about 180°F/82°C). Cook 4–6 minutes, then carefully turn the fish and cook another 2–4 minutes, until the thickest part reaches 130°F/54°C and flakes easily.

Step 7: Emulsify and serve

Remove from the heat and swirl in the remaining 1/4 cup (60 ml) olive oil by gently shaking the pan until the sauce turns glossy and velvety. Let rest 5 minutes. Sprinkle with parsley and serve the cod spooned with plenty of Vizcaína sauce. Excellent with crusty bread or boiled potatoes.

Pro Tips

• Skin-on cod helps emulsify the sauce; collagen from the skin gives body and sheen.
• Keep heat gentle. A near-simmer prevents the fish from tightening and keeps the sauce from splitting.
• For a restaurant-smooth finish, pass the blended sauce through a fine-mesh sieve.
• Taste for salt only at the end—cod brings seasoning even after desalting.
• Jarred choricero paste is a great shortcut and typically more consistent than dried peppers.

Variations

• Tomato-kissed: For a slightly fruitier profile (regional variation), add 2–3 tbsp tomato purée in Step 4 and cook 5 minutes before blending.
• Pepper substitutes: If choricero peppers are unavailable, use 6 dried ñora peppers or 2 large mild anchos (not smoky), prepped the same way.
• With potatoes: Add 1 lb (450 g) waxy potatoes, boiled and sliced, to the sauce in Step 7 to serve as a complete one-pan meal.

Storage & Make-Ahead

Make the Vizcaína sauce up to 3 days ahead; refrigerate covered. Rewarm gently before adding the fish. Leftover bacalao keeps 2 days in the refrigerator; reheat very gently until just warmed through—do not boil or the fish will toughen and the sauce may separate. The sauce (without fish) freezes well for up to 2 months; thaw overnight in the fridge and reblend if needed. Cook the fish fresh for best texture.

Nutrition (per serving)

Approximate: 520 kcal; 35 g fat (5 g saturated); 18 g carbohydrates; 4 g fiber; 35 g protein. Sodium varies significantly based on desalting thoroughness.