Preheat your oven to 180C/Gas 4.
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 loins with salt and milled pepper and rub the olive oil all over. Pan fry on the skin side 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 rapeseed oil if required.
Cook the chorizo over a medium heat until the oils come out, next add the potatoes and sprinkle the paprika over, continue frying until the potatoes start to crisp on the edges while stirring every so often. Add the peppers and chard, pop a lid on, 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, seabass and all other white fish.