Peel and cut the potatoes into cubes. Bring a saucepan of water to the boil. Add the cubed potatoes and cook until tender, drain.
Place a large frying pan over a medium-high heat, season the cod fillets with salt and freshly ground pepper and rub the oil all over. Pan fry for 5 minutes, transfer to an oven tray and cook in the oven for about 10 minutes, depending on the thickness of your cod.
Meanwhile, in the same pan, add the chorizo and a little more oil if required.
Cook the chorizo over a medium heat until the fat is released, next add the potatoes and sprinkle with the paprika. Continue frying until the potatoes start to crisp on the edges, stirring every so often.
Add the peppers and spinach, cover with a lid, turn the heat down and cook until the chard wilts.
Divide the potato and chorizo mixture between your plates, top with the cod and serve.
This dish works wonderfully well with haddock, hake and all other white fish.