What is Merluza a la Koskera?
Merluza a la Koskera is a classic fish dish from the Basque Country in northern Spain. It features hake (merluza) cooked gently in a green sauce (salsa verde) made with olive oil, garlic, parsley, and white wine, and typically accompanied by clams, green peas, white asparagus, and hard-boiled egg.
Elegant and nourishing, this dish reflects the Basque culinary philosophy: fresh, high-quality ingredients, prepared simply to let their natural flavors shine.
🧾 Ingredients of Merluza a la Koskera
Here are the traditional ingredients you’ll need:
For 4 servings:
- 4 hake fillets (preferably thick, skin-on)
- 200g clams (cleaned)
- 100g green peas (fresh or frozen)
- 6–8 white asparagus spears (cooked or canned)
- 2 hard-boiled eggs (halved or sliced)
- 3 garlic cloves (finely chopped)
- 1 small onion (optional, finely chopped)
- 150ml dry white wine
- 500ml fish stock (or water with fish bouillon)
- A large bunch of fresh parsley (finely chopped)
- Extra virgin olive oil
- Salt and black pepper to taste
- Flour for dusting the fish (optional)
👩🍳 How to Make Merluza a la Koskera – Step by Step
🥣 Step 1: Prepare the Sauce Base
- In a wide pan, heat olive oil and gently fry the garlic (and onion if using) until translucent.
- Add the flour (optional) to create a light roux, then pour in the white wine and let it reduce for a minute.
🌿 Step 2: Add the Green Sauce Ingredients
- Add the fish stock and stir until slightly thickened.
- Stir in the chopped parsley—this gives the dish its signature green color.
- Season with salt and pepper to taste.
🐟 Step 3: Cook the Hake
- Gently place the hake fillets into the simmering sauce, skin side down.
- Simmer on low heat for about 6–8 minutes, depending on the thickness.
🦪 Step 4: Add Clams, Peas, and Asparagus
- Add the clams around the fish and cover the pan for 3–5 minutes, or until the clams open.
- Toss in the green peas and white asparagus, warming them through gently.
🥚 Step 5: Garnish and Serve
- Top the dish with slices or halves of hard-boiled egg for color and richness.
- Serve hot, with crusty bread to soak up the flavorful green sauce.
📖 A Short History of Merluza a la Koskera
The name “a la Koskera” refers to the style of cooking from Koskerra, an old Basque culinary tradition. This dish is one of the most famous preparations of hake, a mild white fish that’s beloved across Spain and especially in the Basque coastal regions.
The green sauce (salsa verde) is a staple in Basque seafood recipes, traditionally made with parsley and garlic emulsified with olive oil. The addition of clams, peas, and asparagus came later, enriching the dish with color and texture.
💡 Cooking Tips
- Fresh hake is ideal, but high-quality frozen fillets also work well.
- Do not overcook the fish—it should be flaky but moist.
- The clams should be fresh and tightly closed before cooking. Discard any that don’t open.
- Add the parsley just before serving to retain the vibrant green color.
🥰 Why You’ll Love This Dish
✔️ Light and healthy – Low in fat, high in protein
✔️ Perfect for elegant dinners or casual lunches
✔️ Naturally gluten-free (if flour is omitted)
✔️ A delicious way to explore traditional Basque seafood recipes
If you enjoy Merluza a la Koskera, you may also love Bacalao al Pil Pil or Morcilla both flavorful and rich Spanish seafood dishes from different regions.
🏁 Final Thoughts
Merluza a la Koskera is not just a recipe—it’s a piece of Basque cultural heritage. Simple ingredients come together in a way that’s both nourishing and refined, reflecting the culinary excellence of northern Spain.
It’s a must-try for anyone interested in authentic Spanish cuisine, and especially for seafood lovers looking to expand their repertoire.