Prepare the cod. If it's salty, desalt cod overnight, taking care to renew the water frequently.
Once you have removed the maximum amount of salt is introduced into hot water for 3 minutes, pull it and remove skin and bones. If it's not salty, just pull it into small pieces.

Prepare stuffing. Clean and chop the onions and garlic.
Put some oil in a pan.
Fry the onions and garlic over low heat until onion is transparent.
Add the cod and stir.

Sprinkle with flour, stirring constantly.
Add the milk little by little and stir to a smooth paste. Season with a little nutmeg, salt and pepper.
Cook for about 10 minutes, stirring, until sauce thickens. Leave it to cool as it's easier to handle.

Filling. Fill the peppers and close with a toothpick.
Reserve the peppers that have been broken, or are useless to fill.
Place the peppers in an oven tray to warm in the oven later.

Prepare the sauce

Put the remaining peppers in a bowl with tomato sauce, cream, white wine and mix in a blender.

Bake

Cover the piquillo peppers with the sauce and put the train in preheated oven at 100 ° C for 5 minutes, taking care that they don't get too dry.

Presentation
In the serving dish, place the peppers fan-shaped and add some sauce to the center of the plate, accompanied by a slightly fruity white wine.