Wash the fish and cut into large pieces. Bring 3/4 litre of lightly salted water with a small bay leaf to the boil and let the fish simmer covered in it for 5-7 minutes. Clean, wash and thinly slice the celery.
Steam celery in little boiling salted water for 1-2 minutes. Bring 200 ml fish stock and cream to the boil. Dissolve the crab soup paste in it while stirring. Season to taste with salt and pepper. Drain the fish and celery and carefully fold into the sauce.
Wash the dill, dab dry, cut finely and sprinkle on top. Boiled potatoes taste very good with ragout.