In a wide casserole we cook the onion with the bay leaf and a glass of water. When they have boiled for five minutes, add the potatoes peeled and cut into irregular pieces, letting them cook for about 12 to 15 minutes, until they are tender, but without falling apart.
We clean the fish well and we salt with a handful of coarse salt, letting the salt be in contact with the slices for an hour. Then we wash the slices to remove the salt and reserve.
We put the hake slices in the casserole and cook them for five minutes, -depending on the thickness, one or two more minutes may be necessary- and we cut the cooking by adding half a glass of cold water, so that they do not overcook us. Remove from the heat and let it rest for five minutes.
In the meantime we prepare the garlic with the extra virgin olive oil and the sliced garlic. When these take color, we turn off the heat and add the paprika, stirring slightly and letting the oil and garlic soak in. Add half a ladle of the potato and fish stock, wait a minute for the lees to settle, and serve the garlic on the hake slices.