Poach the little carp or trout for 10 minutes in salted water while you prepare the crumbs. Lift the fish, remove all the flesh from the skin and bone and flake finely. Work it into the butter and blend with all the other ingredients, including the panada. Finally, blend in 2 eggs, and when quite smooth fill the large carp and sew up the belly.
Make any surplus forcemeat into balls, flo