Bacalao al pil-pil

Bacalao al pil-pil is a Basque dish of desalted salt cod, served in a sauce emulsified from olive oil, garlic and chilli, with the cod's own gelatin. It is one of the best-known preparations of salt cod in the Basque Country.

What it really is

The dish is built on salt cod (bacalao), which is soaked to remove most of its salt before cooking. The fish is set skin side up in a clay or earthenware dish with olive oil, garlic and dried chilli, and is cooked gently over low heat. As the fish warms, it releases gelatin into the oil. The cook then moves the dish in a rotating or shaking motion, so that the gelatin and the oil bind into a thick, pale emulsion. This shaking is what gives the sauce its name, from the sound of the pil-pil motion in the pan.

The sauce is the defining feature. A similar cod dish in Basque and Spanish cooking, bacalao a la vizcaina, uses a tomato and pepper sauce, and bacalao al ajoarriero uses potato and a tomato base. Neither depends on an emulsion of oil and fish gelatin. Pil-pil is made without cream, flour or egg.

How it's served

• Served hot in the earthenware dish in which it was cooked.
• Usually presented as a portion of cod on the bone with sauce spooned over.
• Eaten with bread to take up the sauce.
• Often served as a main course or as a starter in Basque bars and restaurants.

How to write it on the menu

• Name the main ingredients: salt cod, olive oil, garlic and chilli.
• State that the dish has no added dairy, egg or flour, but that the sauce is an emulsion of oil and fish gelatin, so it is not a light dressing.
• Allergen note: contains fish. Gluten-free as classically made, but check any bread served with it.
• Specify the variant if it is made with a different salt cod cut or with extra garlic or chilli.