Heat the oil in a large skillet or pan with a lid over medium heat.
Sauté the leeks or onion until they begin to soften.
Stir in the garlic, red pepper, zucchini, basil, oregano, paprika, salt and pepper.
Cook for a couple of minutes until they begin to soften a little.
Add the chickpeas and the tomatoes.
Fill the tomato can a quarter full with water and pour that in as well.
Bring the mixture to a boil, then reduce the heat and simmer for 5 minutes, stirring occasionally.
Nestle the cod loin or fillets in with the tomatoey ragu.
Sprinkle about half of the spring onions (scallions), over the top (if using).
Cover the pan and simmer over low heat for about 10 minutes or until the fish is opaque and cooked through.
Serve garnished with parsley and remaining spring onions.