It's not the prettiest creature of the seas so it is best to disguise its appearance in a variety of recipes.
One of the simplest being in a guisada - this is when one food is roasted or cooked. A guisado, meanwhile, is a stew of different foods.
This recipe comes with a health warning. Preparing this dish is definitely not for the more squeamish cooks among you.
1 Lamprey of about 1.5 kilos
200 mils of olive oil
200 mils of wine vinegar
125 mils of dry red wine
2 cloves of garlic, finely chopped
Pinch of ground cinnamon
Salt and pepper
Wash the lamprey well under hot water and pat it dry.
Remove the gall bladder from beneath the mouth. Slit the fish lengthwise along its belly and collect the blood. Then gut and clean the fish and rinse out the belly cavity.
Combine the blood, olive oil, wine vinegar and wine. Bring to the boil in a large pan. Add the garlic and season the liquor with salt, pepper and cinnamon.
Lay the fish in the cooking liquor and bring it back to the boil.
Cover and leave on a low heat for around 25 minutes without letting it boil.
Then cut the fish into portions and return it to the cooking liquor.
Serve immediately with fresh white bread or with rice. Or, do as they do in Galicia, and serve it with toasted breadcrumbs.