500 gmbacalao, soaked overnight in four changes of water80 ml(1/3 cup) olive oil8golden shallots, diced2garlic cloves, finely chopped4Dutch cream potatoes, cut into 4cm pieces2leeks, washed, sliced 1cm thick2fresh bay leaves1 tspsweet paprikaPinchof saffron threads2baby leeks, washedFish stock1 kgcod bones1leek, coarsely chopped1onion, coarsely chopped1celery stalk, coarsely chopped
For fish stock, rinse bones thoroughly under cold running water to remove blood. Combine in a large saucepan with remaining ingredients and enough cold water to just cover. Bring slowly to the boil over medium heat, skimming scum from surface, and cook over low heat until stock is well-flavoured (1-2 hours). Cool, then strain and reserve 1 litre. Remaining stock will keep frozen for up to 1 month.
Rinse bacalao under cold running water, place in a saucepan, cover with fish stock and bring to a simmer over medium heat. Reduce heat to low and simmer until cod is just cooked through (6-8 minutes). Remove cod from liquid (reserve liquid), set aside to cool slightly (5-10 minutes), then coarsely flake flesh (discard skin and bones).
Meanwhile, heat oil in a saucepan over medium heat, add shallot and garlic and sauté until translucent and soft (5-10 minutes). Add potato, leek, bay leaves, spices and reserved cod stock, bring to a simmer, then reduce heat to low and simmer until potato is just tender (15-20 minutes). Add cod and simmer until potato is very tender (5-10 minutes). Season to taste with freshly ground black pepper and keep warm.
Meanwhile, blanch baby leeks in a saucepan of boiling water until tender (1-2 minutes). Drain and thinly slice on an angle. Serve soup scattered with baby leeks.
This staple of Basque cooking is more of a stew than a soup.
Bacalao (salt cod) is the favoured fish of the region, and of Spain
generally. Usually this recipe is made with stockfish (cod that has
been salted and dried until it's as hard as wood). You can use this
if you like, but you may need to soak it for longer than bacalao.
If you have trouble finding bacalao, you can also make your own by
salting a piece of cod for a few days beforehand. A lighter version
of this soup can be made using fresh cod (bacalao fresco). You'll
need to begin this recipe a day ahead.