Bacalao, pan-fried with potato and egg

Salt cod is a staple in many countries -it's a traditional dish in France, where it's puréed with potato to create the classic dish brandade, and also in Jamaica, where it's usually served with ackee. But it is thought that the Basques were the first to dry cod with salt on their long ocean voyages, some 500 years ago, and spread the skill to the far-flung territories they traded with. Unsurprisingly, salt cod is still widely eaten in Spain and Portugal.

It is not a food you can cook on impulse, as it needs preparation, but if you have the time there are a lot of delicious recipes for salt cod out there. This one is based on a traditional Portuguese recipe, where it is often served for brunch, although in Portugal the eggs are usually scrambled rather than boiled. I had this for my supper on Christmas Eve - it satisfied my need to make something special that night but was also a lighter dish before the onslaught of rich seasonal fare.

What you need: 
1 piece of dried salt cod, about 5 inches square
A few small potatoes, sliced into rounds about 3mm thick
1 large egg
1 onion, sliced thinly
Olive oil
Butter
Black pepper
Fresh parsley, finely chopped
A few stoned black olives (optional)

What to do:
Put the fish in a bowl and cover it in cold water. Soak for at least 12 hours and change the water regularly.

Put the fish in a pan, cover it with water and bring it to the boil. Turn the heat down to a simmer and let it cook for about 20 minutes, until it flakes easily. Boil the egg so it's firm. Drain the fish, let it cool on a chopping board then flake it, removing any bones and skin. Shell the boiled egg and set both aside.

Heat some olive oil and a knob of butter in a heavy sauteuse on a medium heat. Fry the potatoes until they start to turn golden and crisp up. Add the onions about halfway through and cook until they start to caramelise slightly. Together these need about 20 minutes.

Turn the heat down.  Quarter the boiled egg then chop roughly and add it and the fish to the pan. Stir them through to heat up, about 5 minutes. Sprinkle with the parsley and garnish with the olives, if using. Eat with a green side salad.

Cook's tips: 
A good fishmonger will have salt cod and should cut you a piece to size. Supermarkets with a good ethnic section should also stock it, but it will be sold in a plastic vacuum pack rather than fresh out of the fishmonger's box - follow the packet instructions for soaking, in that case. You can also buy it online.

The soaking is essential, as salt cod is extremely salty - 12 hours is the absolute minimum you should soak it for, ideally a good 24 hours. The fish will swell as it rehydrates and may appear to be too much for one person but don't be fooled - it will shrink back slightly on cooking and when you flake it you will most likely be removing a large piece of spine along with the pin-bones, so you'll end up with a sensible amount of fish.