This is a great way to serve cod in which courgettes are transformed into a seaweed nest for the fish. It makes a spectacular-looking and great-tasting dish.
Preheat the oven. Wash and dry the courgettes and trim off both ends. Grate the courgettes into a bowl and toss them with the salt. Leave for 10 minutes. Using a large frying pan, sauté the onion and garlic in the oil, stirring until they are softened but not allowing them to colour. Squeeze the liquid from the courgettes by handfuls and then add the courgettes to the pan. Discard the liquid. S