Rinse the fish ends of cuts, put in a large saucepan, pour in 2.5 liters of water and bring to the boil under a high heat. Slack the fire, salt a bit and cook for 1 hour. Strain the broth. Peel the pickled cucumbers and cut them into small slices. Pour a little water into the pan, bring to the mild boil, put cucumbers and parboil for 7-10 minutes. Place in a colander. Peel the lemon so that the pulp is visible, and cut along the wedges between the films. Cut fish fillet into large cubes, cover with small amount of broth, bring to a boil and parboil for 3-4 minutes. Peel onion and chop it very finely. Heat oil in a large saucepan with a thick bottom, put onion and fry for 5-7 minutes. Add sugar and tomato paste, and fry for 3 minutes. Pour in broth, add pickles and cucumber brine to taste, green and black olives and bay leaf. Pepper, bring to a boil and cook for 5 minutes. Put the fish, capers, dill and slices of lemon pulp on plates. Ladle out kalja in plates and serve at once.