Rinse the hake carcass in cold running water, peel the onions, and wash the carrots and remove the skins.
Grate the carrots onto a coarse grater and chop the onion into small cubes. Place the onions and carrots in a slow cooker to fry in a spoon of vegetable oil for 7 minutes.
At this time, clean the fish if necessary, then cut it into medium pieces and roll in flour with a little salt for taste.
Add tomato juice, salt and spices to taste to the multicooker with the fried vegetables. Cook everything together for another 3 minutes, and then transfer from the multicooker to another suitable container. Wash the multicooker bowl.
Place the fish pieces into a clean slow cooker and fry them in the remaining oil on both sides for about 3 minutes. Then add vegetables to them and cook for about 5 minutes.
The finished fish can be served with chopped fresh vegetables and herbs, and you can also supplement the serving with vegetables from the slow cooker, which act as a sauce for the fish.