Cut the baccalà into 5cm-long pieces. Pat them dry with some kitchen paper and flour them on both sides. Peel the potatoes and cut them into 5mm thick slices, then flour them, too.

You might find yourself with just a little bit of oil left in the pan. Discard the rosemary and the garlic and, when the pan is not hot anymore, wipe it clean with some kitchen paper. You’ll be able to use it to cook the tomato sauce now and you’ll save a pan.

Now prepare the tomato sauce. Pour the remaining olive oil into a large pan, add the thinly sliced onion and the last clove of garlic. Season with a generous pinch of salt: this will help you cook the onion and prevent it from burning. Cook the onion of medium-low flame for about 10 minutes, until soft and translucent.

Add the chopped, crushed tomatoes into the pan and cook for 10 minutes, until they collapse into a sauce. Taste and adjust with salt: you want the sauce to be slightly under-seasoned, as usually the cod is quite salty on its own.

Add the cod and potatoes back into the pan, reduce to a simmer and cook for about 10 minutes, so that all the flavours will be mixed together. taste for the last time and see if you might need a last sprinkle of salt. Sprinkle with some finely chopped parsley and serve hot.

Any leftover can be kept in the fridge for a couple of days. Gently reheat before serving, even though I must confess I also like baccalà alla fiorentina, straight from the fridge.