To make salt cod omelette we will use desalted, flaked cod, which is usually cheaper than loins. In this recipe the cod needs to have just the right amount of salt. We desalt it ourselves and, once it is just right, we freeze it. On the day we want to cook a recipe with desalted cod, we just need to remember to move it to the fridge the day before. Another option is to buy cod that has already been desalted.