Of flour, a pinch of salt, 30 g butter , egg, 1 tsp (5 ml) vinegar and a little lukewarm water, prepare a soft dough, which is drawn on cloth (for strudel). The filling is made from milled in salted and acidified with vinegar boiling water fish fillets, drained, cleaned of skin and bones crushed and seasoned with parsley and lemon pieces (peeled and seedless). Insert the stuffing, then using a towel wrapped roll. Roll is wrapped like a snail in a greased baking dish with butter, sprinkle with remaining butter and bake 25 minutes in a hot oven. Cut with a sharp knife and serve with lemon slices.