Salt cod - bacalao to the Spanish, baccalà in Italy and morue in France - lends itself to lots of different cooking methods. This is the French version, where the fish is cooked and puréed with potato and lots of garlic.
Traditional salt cod is split like a big kipper and salted, which means you end up with loads of fiddly bones. Instead, if you can get a hold of any, try to buy salted cod loins, which are nicely trimmed with no bones and skin. I’ve allowed for