Cut the onion into half rings, grate the carrots on a coarse grater. Fry the vegetables in vegetable oil until al dente. Add spices, sugar, vinegar and ketchup. Cut the olives into slices and add them to the vegetables. Pour in a glass of boiled water, mix everything and reduce the heat to medium-low.
Cut the fish fillet into portions and put them in a vegetable marinade. Cover the pan and leave to simmer for 20 minutes. During this time, we do not touch the fish and do not turn it over/ stir it. Serve the finished fish with your favorite side dish.