Take a kilo of sweet potatoes and another of potatoes, peel them and cut them into big pieces. If potatoes are not big enough, don't cut them. Then take a kilo of cherne or salted corvina, previously desalted.
To desalt the fish, take the salt off with a cloth and put it under the tab with cold water and then leave it covered with water the day before. Put the potatoes, sweet potatoes, the fish, one onion and a sprig of parsley into a cauldron with water. Let it cook until potatoes are soft. Strain everything and serve without the onion and the parsley. Sancocho is served with red mojo and 'pella de gofio' (gofio flour is kneaded with a little bit of water and oil until it achieves a texture similar to bread).